But what exactly are low rolling resistance tires, and how do you spot them the next time you buy "shoes" for your car?
First of all, let's learn the definition. Tires with low rolling resistance - exactly what you think they are. They form a lower resistance (less friction) during rolling compared to other tires. In other words, how can they be cat on the road? Energy is constantly wasted by the heat that is generated by the contact of the tire with the track surface and the tire, in the tire itself and between the tire and the rim.
Keep in mind that rolling resistance and traction, or handling, are two very different things. While they are indeed related, they are not interdependent. This means that the tire will not necessarily lose grip characteristics as its rolling resistance decreases.
A simple rule of thumb is that the stiffer the tire, the lower its rolling resistance. That is why it is very important to monitor the proper level of tire pressure. No matter what type of tires you use, the main thing you should do to save fuel is check your tire pressure and keep it at the correct level.
What affects the level of rolling resistance? Although there is no "written law", a 10% reduction in tire rolling resistance will increase fuel economy by 1-2%, although this figure will vary by tire and vehicle.
How is rolling resistance determined? The Society of Automotive Engineers has developed a way to determine the level of rolling resistance - by determining the amount of force required to roll a tire on a dynamometer at 50 mph (SAE J1269 testing). Test results for different speeds will be different, but the "gold standard" is SAE J1269. Typically, rolling resistance varies by 20 to 30% even with tires of the same size and type.
Let's talk about choosing new "shoes" for your car. If the car is more or less new, then the main criterion for buying is usually the make and model of the tire that it was equipped with on the conveyor.
The quality of modern car tires determine parameters such as rolling resistance coefficient, car handling on wet and dry surfaces, braking properties, aquaplaning performance of a new tire and its wear resistance, noise, mileage, price, comfort...
However, the problem is that for different participants in the car market - automakers, tire sellers and drivers who buy tires in the secondary market - these parameters have different priorities.
Who likes what
It's no secret that each automaker has its own requirements for tires intended for the initial configuration of a car. However, they are by no means universal. different companies they may differ significantly.
For example, one automaker puts forward very strict requirements for the coefficient of rolling resistance, which directly affects the economy of a car, while another will have them much softer. One company is extremely demanding on hydroplaning parameters worn tire, and for the other they are not critical. At the same time, the requirements for a tire for secondary market, will also be different.
The explanation is simple: the car, first of all, needs to be sold, so the characteristics of all its components are subject to a single goal. The consumer wants a car with low fuel consumption - here you have new fuel-efficient engines and tires with a lower coefficient of rolling resistance. Comfort is important - here comfortable lounge, energy-intensive suspension and quiet tires. Thus, each element forms an idea of the car as a whole.
And in the secondary market, the consumer is guided by some of his preferences, often completely different from the views of automakers. For example, according to marketing research, the price and design of a tire are very important for the end user...
One in many faces
Thus, in order to meet different requirements, tires cannot have the same parameters, and therefore will be different. That is, the dimensions, design and name will be the same, but structurally, albeit slightly, the tires will differ. For example, to have different radial or diagonal stiffness, a different tread filler and, possibly, a slightly modified tread pattern. Let's say slightly offset blocks, an increased number of lamellas...
However, according to manufacturers, these changes will not affect the feelings of the end user. Indeed, in any case, these will be good, high-quality tires, although with an emphasis on some "own" parameters.
However, when delivering to the conveyor, it is important to maintain the specified parameters on the entire array of tires. At the same time, it is considered quite satisfactory if the characteristics of 10% of the produced tires do not meet all the requirements of automakers. These 10% (this is not a marriage!) And enter the secondary market.
At the same time, if the aftermarket demands more, additional tires are produced to meet demand. For the secondary market, the specification is produced as close as possible to the requirements of the market.
Economy tires: Is it possible to reduce fuel consumption due to tires
In the advertising materials of tire manufacturers, along with the words "durability", "good grip", "fast braking", there are always assurances of "economy", that is, a noticeable reduction in fuel consumption. Explained similar effect lower rolling resistance.
Of course, the speed with which the fuel level indicator in the tank tends to zero is influenced by many factors: from driving style to the mass of passengers. Also, there is no need to talk about "frugality" winter tires, since during their operation completely different qualities come to the fore, incompatible with the ease of rolling. Therefore, today we will get acquainted with the most common Russian market summer economical (or energy-efficient) tires and find out whether it is worth counting on serious budget savings when using them.
A bit of theory
For novice car enthusiasts who first learned about tires with low rolling resistance, a logical question arises: what resists what and how does this relate to fuel consumption? The fact is that the outer (aka running) part of the tire, in contact with the road surface, is somewhat deformed - from round it becomes flattened - and forms the so-called contact patch. When the car starts to move, the deformation process becomes continuous, the "spot" moves along the tire and provides traction. Thus, the less energy required to overcome the change in tire shape and the more easily the contact patch disengages from the pavement, the lower the amount of rolling resistance.
The deformation and contact patch is best demonstrated by a half-flat tire.
Main design characteristics tires that affect how easily it rolls on the road are the elasticity of the tread and sidewall materials, as well as the "stickiness" of the tread material to the road.
Among tires of the same diameter, wider tires with a larger contact patch have increased rolling resistance. Not economical and sports tires designed for driving high speeds, since the composition of the material from which they are made should provide maximum grip with the road surface.
By the way, the easiest way to reduce rolling resistance is to pump up tires. Here, the deformation decreases, and the contact patch becomes smaller. It’s just not worth pumping the wheels above the recommended values, since this significantly increases the braking distance, the car breaks into a skid more easily, and the ride comfort noticeably suffers, especially on rough roads.
Since tires account for about 20% of total fuel consumption in a typical passenger car, it is not surprising that tire manufacturers are trying to increase the attractiveness of their products through this indicator. On average, reducing resistance by 10% saves about 1-2% of fuel.
What manufacturers promise us
Let's see how manufacturers try to reduce this "harmful" indicator, how effectively innovations manifest themselves in real conditions and, most importantly, how such changes affect such important properties tires like stability on the road various conditions and braking speed.
In tests of summer tires commissioned by reputable domestic and foreign automotive magazines, the characteristic "low rolling resistance" most often has products of companies, and. Of course, almost all manufacturers offer such rubber today, but we will limit ourselves to the brands mentioned above that are popular in Russia.
Flagship of energy efficient products Nokian Tires are tires. As stated on the concern's website, the rolling resistance of these tires is reduced by 15% compared to the previous model - . If we take "normal" tires, then the reduction reaches 40%.
Attempts to understand how such impressive results, end with press release routine phrases about "specially designed tread and unique rubber compound composition." The only detail voiced by Nokian marketers is that the tires contain Finnish pine oil.
Another well-known manufacturer tire also has in its arsenal a "thrifty" tire -. However, here, too, they speak very sparingly about technology and design. Michelin is proud to be the first to add silicon (or, as it is also called, silica) to the rubber compound. However, today this mineral has become an integral part of the tires of any manufacturer. But on the merits of the issue there is practically no information: "Reduced weight, unique composition, innovative design ... "" Tire buyers are promised a saving of eighty liters of fuel over the entire mileage of a set of tires, which, in turn, will be ten thousand kilometers longer. All this, of course, on average and compared to all the same " regular tires.
However, it would be naive to expect that tire manufacturers will begin to generously share the developments of engineers and technological secrets. Here it says Pirelli company about "innovative materials" and "ELRR (Extra Low Rolling Resistance)" - an ultra-low rolling resistance system used in tires.
Slightly more verbose representatives of GoodYear, saying that EfficientGrip tire has an "improved framework using special materials, lightening the weight of the product; an improved process for the development and production of a rubber compound with a new compound that delivers superior mileage, wet braking and rolling resistance." It also claims to reduce fuel consumption by 1.9% "compared to the top four competitors." , what kind of competitors, however, is not reported.
The advantages of an economical tire should be "a new silicon composition of the tread material, a modified contour and an asymmetric tread shape." The rolling resistance of this tire is 12% lower than that of the predecessor ContiEcoContact EP.
Summarizing disparate information, we can conclude that in recent years, the main efforts of designers have been aimed at reducing the weight of the tire by reducing the number of cord layers and tread thickness, as well as using it as part of the rubber compound synthetic materials, which have minimal energy loss during deformation.
Practice is the criterion of truth
Well, it's time to move on from the beautiful promises of the manufacturers of automobile "shoes" to practical results and see what the car owner gains and loses by purchasing economical tires.
The main question of all tests: is it possible, with a significant reduction in rolling resistance, to maintain at a high level such tire qualities as handling and grip on dry and wet roads, resistance to aquaplaning, good braking and so on.? And here the test reports are inexorable: perfect combination no manufacturer has yet been able to achieve efficiency and safety.
Yes, all "economy" tires that took part in the tests show a significant reduction in rolling resistance and more. low consumption fuel, but this always leads to a noticeable deterioration in other characteristics, albeit not fatal. So, the "green tire" Hokian demonstrates mediocre traction and handling on dry surfaces. A car with tires will not have the best better handling on wet pavement and hydroplaning. Pirelli's ultra-low rolling resistance system results in a noticeable increase stopping distance especially on wet surfaces. Owners Goodyear Efficient Grip it is worth being as collected as possible during the rain, especially if there are deep puddles on the way. Tires keep the driver in suspense on wet pavement and give a noticeable increase in braking distance on dry pavement.
In fairness, we note that all of the listed shortcomings are more or less noticeable in tests conducted in extreme conditions specialized landfills. During normal driving around the city and country roads, the probability of a serious impact of the "minuses" of economical tires on safety and driving comfort is extremely small.
The most complete defects of tires can be identified only at the test site
Thus, ceteris paribus energy efficient tires really live up to their name and are able to reduce fuel consumption. Another thing is that even the maximum results achieved under ideal test conditions are measured by 100-200 grams per 100 kilometers or saving several tens of liters per year. Accordingly, with daily (including weekends) trips of 100 kilometers, gasoline costs will be reduced by 100-150 rubles per month. In reality, the reduction in costs will be even less.
So it turns out that, choosing a new thing for your " iron horse”, First of all, attention should be paid to the conditions in which it will be operated, handling and good grip. And if economy (albeit small) is also attached to this - wonderful, nice bonus hasn't bothered anyone yet.
While there isn't much a driver can do with the first two after they've already bought a car, the question is, can low rolling resistance eco-tyres have a noticeable impact on fuel consumption, operating costs and the environment? The answer is yes.
About 80% of the mass of a tire is rubber, which is a viscoelastic material that, due to its natural properties, converts part of the energy into heat when compressed or stretched. Rolling resistance is caused primarily by the fact that the sidewalls and treads are constantly compressing and stretching as the wheel rotates and redistributes the load (when the weight of the car causes the sidewalls to "inflate" and the tread to "flatten" against the road).
In the past, rolling resistance has not been subjected to in-depth research or measurement, so there is very little information for comparison. Be that as it may, given that every gallon of fuel saved reduces the personal cost of drivers and America's dependence on oil, as well as reduces carbon dioxide emissions into the atmosphere, information on rolling resistance and its impact on fuel consumption will be available to a more reasonable extent in over the next couple of years thanks to federal and California laws.
Although in the past rolling resistance has often been reduced to the detriment of wet grip and tread wear, the latest high-tech fuel-efficient tires with reduced rolling resistance do not lose their other necessary qualities thanks to new rubber compounds and production processes optimizing tire weight.
In 2009, so many manufacturers released their tires with low rolling resistance, and the team Tire Rack decided it was time to evaluate the impact these tires have on fuel consumption, and also to make sure that wet grip was not sacrificed for this. Consumption measurement became part of the road test, which also evaluated wet and dry grip during cornering and braking.
Cars
Unfortunately, not all of the latest low rolling resistance tires are available in sizes suitable for conventional tires. test cars Tire Rack, so for this test we had to create a small fleet of hybrid Toyota Prius 2nd generation 2009 model year. All vehicles have traveled the same number of miles and have been used in identical conditions to ensure the most accurate results.
In preparation for the test, the tires were mounted on standard 15x6.0" Prius rims and all four wheels were adjusted to avoid unwanted tire friction on the road, which affects fuel consumption.
Tires
At the start of testing, it was decided that Goodyear Integrity tires (available in the US for 2004-2009 Prius) would be the benchmark during testing. Their results were then compared with other tyres, which ranged from brand new tyres, which are now offered in the secondary market for compact economy cars, to the Goodyear Assurance ComforTread tires released in 2004, before eco-tires were popular. They are distinguished by a compacted rubber layer (by 20%) between the tread and belts, which puts ride comfort and durability above reducing fuel consumption.
Only new tires in size 185/65R15 with full tread depth were selected for testing, belonging to several categories:
All-season tires are the preferred choice for drivers living in geographical areas with temperate climate where there may be only a small layer of snow on the roads. Summer tires are for those who live in the "sun belt" where tires only need to handle dry and wet surfaces, or for "snow belt" drivers who change tires to winter tires every year.
Tire pressure
It was possible to start with a higher than standard cold tire pressure to reduce fuel consumption, but it was decided to stick to the manufacturer's recommendations. In addition, according to Tire Rack experts, although low level pressure increases rolling resistance, more high level does not reduce it to the same extent.
The cold tire pressure was set at the recommended level of 2.5 atmospheres front and 2.3 atmospheres rear. This was done in the early morning after the cars had been parked on the street all night. The pressure was also checked at noon when the team finished their tests and the air and road temperatures were at their peak. As expected, the pressure in the warm tires increased to about 2.7 atmospheres in front and 2.5 atmospheres in the rear (±0.03 atmospheres).
Road test in real conditions
During the road test, each tire travels 885 km, making many laps in a 10.6 km loop consisting of sections of federal highway (105 km/h), state highway (90 km/h) and country roads (65 km/h), plus two stop signs and one traffic light on each lap. During the test, pilots poured into medium-density traffic at an average speed of 65 km/h.
To maximize fuel consumption, road tests were conducted on dry surfaces only. Since tire treads experience more resistance when passing through water than through air, rain-soaked roads would mean that the depth of the water layer would vary, making accurate measurements impossible.
Since the purpose of the test was to compare the results that would be shown by a normal driver, the pilots had to stick to the average flow rate, respecting all restrictions speed limit and maintaining a stable vehicle speed by using cruise control where possible. They also stopped at stop signs and waited at traffic lights for as long as required.
Fuel consumption
Instead of using on-board computer The Prius, which automatically assumes that all wheel configurations are identical when calculating fuel consumption, used Race Technology DL1 GPS data loggers (to measure speed and distance traveled), as well as Linear-Logic ScanGauge II indicators to calculate fuel consumption). Changed during every run. head machine, and every half day the tires were moved from one car to another to maximize the accuracy of the data and eliminate errors caused by the characteristics of each car.
According to the Agency for Protection environment US (EPA) 2009 Prius fuel consumption combined cycle is 5.1l/100km using standard quality gasoline. The hybrids in this test consumed an average of 4.5L/100km with the A/C on. The test drivers believe that the lower fuel consumption is primarily due to vehicle preparation (careful adjustment and control of tire pressure), driving conditions ( dense stream without sharp accelerations), as well as the route itself, along which there were a limited number of stops and which allowed only medium-density traffic.
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Fuel consumption |
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|---|---|---|
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Tires |
Fuel consumption (mpg) |
In % Rel. to the landmark |
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Michelin Energy Saver A/S |
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Bridgestone Ecopia EP100 |
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Yokohama dB Super E-Spec |
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Goodyear Assurance Fuel Max |
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Goodyear Integrity |
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Goodyear Assurance ComforTred |
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Fuel consumption was determined based on GPS distance traveled and ScanGage II fuel consumption data.
In the case of the Prius - and this is one of the most economical cars in America, the difference between the highest and lowest consumption in this test means an annual difference of 79.5 liters of standard quality gasoline priced at approximately $52.50 for drivers driving 24,000 km per year. Multiply that difference by a few years and the value of low rolling resistance tires goes up significantly. In addition, eco-tyres reduce the fuel consumption of other vehicles by the same percentage, so fuel savings from tires with low rolling resistance can double or quadruple, if we take ordinary car with a fuel consumption of 8-10l / 100km or pickups / crossovers that already consume 16-20l / 100km.
Road test results
Segments simulating an expressway, a local road and country road, so the tires were tested in a variety of road conditions - on smooth and uneven concrete, as well as on new asphalt and pavement with "patches". During these segments, pilots can experience the noise level, ride comfort, handling in everyday life, as if they were on their usual route to work.
The very nature of the 2nd generation Prius and its design features mean a high level of external noise intrusion into the cab, which has been proven during testing to mask tire rolling noise, especially at high speeds. Pilots also noted the softness of the Prius's suspension, which results in extra move suspension on rough sections of the road. Thus, everyone agreed that tire choice can have a significant impact on how a car handles and feels.
As you might expect from the name, the Goodyear Assurance ComforTred provides the most comfortable ride of any tire. These tires have proven themselves very well, compensating for the shaking and rolling of the Prius undercarriage on uneven sections and junctions of asphalt pavements. They are followed by the Bridgestone Ecopia EP100, which also successfully minimizes the effect of bumps. pavement. The Michelin Energy Saver A/S is quite a bit behind them, which still allow those in the cabin to feel the “texture” of the asphalt. Michelin's Green X HydroEdge tires are next, while Goodyear Assurance Fuel Max and Yokohama dB Super E-Spec tires fell out of the top group and were quite stiff in large potholes and tarmac joints.
In terms of quietness, again the Goodyear Assurance ComforTred were the first, the rolling noise of which was the smallest compared to the rest. Ecopia EP100, Energy Saver A/S and HydroEdge were not far behind - all tires had the same general level noise, but at different speeds for these tires it amplified, which was the difference. They are followed by the Goodyear Assurance Fuel Max tires, which produce audible noise when driven at high speeds, while the Yokohama dB Super E-Spec and Goodyear Integrity, despite having minimal noise levels, received the lowest scores due to increased noise when driving over large bumps and joints of asphalt pavements.
While the Prius isn't focused on handling, its character and drivability can change dramatically depending on tire choice. The firm ride of the Yokohama dB Super E-Spec is offset by a quick, sporty response to driver input. The same can be said for the Bridgestone Ecopia EP100, which showed consistent and linear responsiveness to control. However, this did not surprise anyone, because only these two tires had an H speed index and were the only summer tires Grand Touring in this test, so they didn't need a tightly siped all-season tread pattern for traction in shallow snow. The handling of the Green X Michelin HydroEdge was also not much worse than these tires, thanks to the high steering response and consistent straight-line contact feel. The Michelin Energy Saver A/S is a bit slower to respond to driver inputs, and there was some viscous steering response at the start of a maneuver. The handling of the Goodyear Assurance Fuel Max may be decent for this category, but it lacks overall feel. The softness of the Goodyear Assurance ComforTred tires resulted in a slightly slower response, which dropped them to the bottom of the rankings, with the Goodyear Integrity being the slowest to respond to steering inputs.
Race track test
The test track is designed to determine the grip stability of each tire in a straight line and in corners. Tires are tested on both wet and dry surfaces. The track is equipped with a sprinkler system that ensures the same conditions during the wet test, which takes place on the first day of the test, followed by the test on the dry track.
All tires were tested in turn by one pilot on one car, so that the difference in the skills of the pilots and the characteristics of the cars did not affect the result. Goodyear Integrity was tested at the beginning, middle and end of each test session to allow any changes in test conditions to be identified and accounted for.
Braking
The braking distance was measured (using ABS) from 80 to 0 km/h to determine the grip of each tire in a straight line. Several tests were carried out, the results of which were recorded by the Vericom VC2000 braking test computer, after which the average result was determined, which is considered a typical stopping distance for each individual tire.
During the wet test, all aftermarket tires scored 32.06-34.29m, with only the Goodyear Integrity standing out from the rest with a stopping distance of 40.17m.
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Wet braking |
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|---|---|---|
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Tire |
feet |
In % Rel. to the landmark |
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Bridgestone Ecopia EP100 |
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Goodyear Assurance ComforTred |
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Michelin Energy Saver A/S |
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Yokohama dB Super E-Spec |
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Goodyear Assurance Fuel Max |
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Michelin HydroEdge with Green X |
||
|
Goodyear Integrity |
||
On dry pavement, the Goodyear Integrity slightly outperformed the rest with 29.5m.
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Dry braking |
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|---|---|---|
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Tires |
feet |
In % Rel. to the landmark |
|
Goodyear Integrity |
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|
Yokohama dB Super E-Spec |
||
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Michelin HydroEdge with Green X |
||
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Michelin Energy Saver A/S |
||
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Goodyear Assurance Fuel Max |
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Bridgestone Ecopia EP100 |
||
|
Goodyear Assurance ComforTred |
||
cornering
To determine the traction of each tire during a corner, a 60-meter round track was used, on which the Prius accelerated until the tires began to lose traction. Races were made in both directions, after which the average value of lateral acceleration was determined (the higher the value, the better the grip).
In wet tests, aftermarket tires again topped the list with an average lateral acceleration of 0.677-0.678 g. At the same time, Goodyear Integrity was again behind the whole group with a result of only 0.601 g. Goodyear tires Integrity also requires a lot of patience from the driver, because it is very slow to regain contact with the road when traction is lost.
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Cornering on wet surfaces |
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|---|---|---|
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Tires |
Average lateral acceleration(g) |
In % Rel. to the landmark |
|
Michelin HydroEdge with Green X |
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|
Yokohama dB Super E-Spec |
||
|
Bridgestone Ecopia EP100 |
||
|
Goodyear Assurance Fuel Max |
||
|
Goodyear Assurance ComforTred |
||
|
Michelin Energy Saver A/S |
||
|
Goodyear Integrity |
||
On dry pavement, as in the braking tests, the Goodyear Integrity were again ahead by a slight margin. Their result was 0.804 g, while the performance of all other tires was slightly lower - 0.743-0.798 g.
Incidentally, as you can see from this list of top-ranked tires in various categories, their names often signal their strengths:
- Fuel consumption: Michelin Energy Saver A/S
- Ride Comfort: Goodyear Assurance ComforTred
- Quiet: Goodyear Assurance ComforTred
- Handling: Yokohama dB Super E-Spec
- Wet braking: Bridgestone Ecopia EP100
- Dry braking: Goodyear Integrity
- Wet cornering: Michelin HydroEdge with Green X
- Dry cornering: Goodyear Integrity
Although the Goodyear Integrity was a true masterpiece in terms of rolling resistance, fuel consumption and grip when it was released, long-term use in the original equipment sector froze their specifications. They have not been improved with new tread patterns, rubber compound additives and innovative technologies, which have been developed over the past few years to create the next generation of environmentally friendly aftermarket tires featured in this test.
Tire Rack encourages drivers to choose tires based on their personal needs. Here are the most important factors:
Vehicle - choose tires whose size and load capacity are suitable for your vehicle. passenger car, van or truck, and which can withstand the weight of passengers and luggage
Geographical region - choose all-season, summer, winter or road/off-road tires suitable for use in the weather conditions of your region (consider road conditions). It probably won't matter how much fuel your tires can save when you can't hit a slope on an icy road with summer tires.
Driving style - Depending on your driving style, choose passenger, touring, commercial or performance tires. The main categories of tires allow you to determine their ratio of comfort, grip and handling.
How you want to save money - choose tires with high wear resistance and/or low rolling resistance that will save you money on tire changes and/or lower fuel consumption. However, remember that the characteristics of your car and your driving style have a much more noticeable effect on fuel consumption than the choice of tires.
So, not all of today's tires are the same, and some of them roll more easily on the road and consume less energy, hence vehicles with low rolling resistance tires consume less fuel.
The difference between the tires with the highest and lowest fuel consumption may not seem significant in this test, but it can become really noticeable with extended use of the tires. While this is a relatively small percentage-wise benefit, fuel economy could be significantly reduced if all 250 million American vehicles were fitted with these tires.
Tires have always been important detail for all drivers without exception, and now the manufacturers have managed to make it a little more environmentally friendly and economical.
Not so long ago I heard about economical tires, supposedly very environmentally friendly, progressive and contribute to fuel economy. Is this true and how do we save fuel? It should be noted that in Europe there is now a fairly advanced trend in the car market. Read more interesting information...
There really are such economical options, and they really save fuel. Many manufacturers now produce them, but only three companies have achieved the most impressive results - Michelin, Goodyear, Nokian. It was these giants who first thought about this parameter and began to fight tire rolling.
What is rolling resistance?
During rotation, the tire experiences many loads, during impacts it deforms, absorbing a significant part of the energy that the engine produces. A wheel with a tire is soft, and therefore it is more difficult to roll it than, say, a completely metal one, which does not deform or dent. But completely metal will make the movement of the car very uncomfortable, the suspension will “die” very quickly, and the braking of such a car will worsen at times. Therefore, the task is not to abandon the rubber tire, but the task is to reduce rolling during movement, that is, to make it tough, but comfortable. Yes, and completely rubber wheel If you don't manage to defeat this force, it's impossible.
Why win at all?
It's simple, the less power - the less power the engine needs to roll these wheels, and, accordingly, fuel consumption will decrease, that is, gasoline or diesel. Yes, and units can be put less powerful.
How are economical tires made?
It should be noted that this is a very difficult task. Manufacturers should not worsen, but improve the characteristics of the rubber (braking, aquaplaning, etc.) and also reduce the roll of the rubber. It changes - it is calculated to the millimeter, the optimal diameter is selected, as well as the optimal composition of the rubber compound, which is less deformed. The compositions of the mixtures are kept in the strictest confidence (each company has its own unique composition), because it is in it that 70% of the improvement in this parameter.
As I already wrote, such companies as Michelin, Goodyear, Nokian have achieved maximum results. These manufacturers have moved from carbon to silicon in their wheels, which not only reduces rolling but also improves cut and puncture resistance.
How much fuel can be saved?
The fuel economy of such wheels can be significant up to 0.5 - 0.6 liters per 100 km. Look at the table.
How to determine them when choosing?
Very simple - each manufacturer has its own abbreviation on wheels.
Usually this is a column from A to G, where A is the tires with the lowest resistance, the most economical. These abbreviations are not always applied to the tire cord, sometimes they are printed on stickers on the wheel.
At Michelin - the abbreviation ENERGY Saver can be used.
Michelin Energy Saver
Goodyear uses its own abbreviation - where LRR (low rolling), ULRR (ultra low), ELRR (extremely low). These abbreviations may be applied to the wheel cord.
Here is such a useful parameter that you also need to know. Other manufacturers are also trying to reduce this parameter and put the designation on the rubber or stickers, so look carefully when buying.
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