Greetings, dear motorists and amateurs!
It is generally accepted by all of us that when installing wheels of a larger diameter on our car, we have to throw out a few extra hundreds into the exhaust pipe, as the pet starts to eat more.
Every day the thought does not leave me that this is not so, I know that a lot has been said and retelled about this, but now I will try to give my hypothesis about this, I think it will seem to you nonsense of an inexperienced boy who does not understand anything, but I don’t have much I understand and do not know in the car and I ask you the nut and key masters not to condemn if something is wrong, but to fix it.
Take a wheel that rolls 1m along the road in one revolution, we find not tricky calculations that for 100 km it will rotate 100,000 times.
Take a wheel of a smaller diameter, which in one revolution rolls 90 cm along the road, by the same calculation we find that for 100 km it will turn 111.111 times (the data is slightly rounded) It turns out that at the same distance, wheels of a larger diameter rotate at a lower frequency, respectively, the shafts, transmission gears and internal combustion engines too.
(Further material from an article from one of the sites) "The speedometer is driven from the transmission by a" flexible shaft "- a special cable that transmits rotation well. Since the same speedometers are found on different cars, a simple gearbox is used in their drive, the gear ratio of which is matched to the car. On a rear-wheel drive, the speedometer usually monitors the rotation of the secondary shaft of the gearbox. This means that the readings depend on the size of the tires, the gear ratio of the rear axle gearbox and the intrinsic error of the device. For example: on Zhiguli, replacing a pair of 4.44 with 3.9 will change the readings by 14%. However, the gears of the reducer are not rubber - therefore, there is no perfect match of the speedometer to the tire size, and they still wear out ... The total error of readings up to 10% and even more is a common thing. Often this explains the records of yard racers.
Front-wheel drive transverse engine speedometers usually "service" the left wheel drive after the main pair. This means that to the error of the speedometer and the influence of the tire size, the effect of the road rounding is added: when cornering to the left, the “indicated speed” is slightly less than in the middle of the car, and to the right - a little more. What is the impact of oversized tires? Replacing a 175 / 70R13 tire with a 165 / 70R13 tire or vice versa changes the speedometer reading by 2.5% "
From the article it is clear that when the tire is worn (that is, when the diameter decreases) and when the wheel moves when turning to the right when the left wheel goes along the outer radius, the speedometer winds up excess.
How do we measure consumption? (your car has 14 wheels) We reset the odometer, drive for example 100 km and look at the fuel gauge, let's say it turned out 10 liters, you are happy!
You changed the shoes of your beauty on 16 discs, reset the odometer and drove off, having driven a hundred, you were horrified, your pet swallowed 13 liters. There is no limit to your disappointment!
In my opinion, this is an illusion caused by incorrect readings of the speedometer due to the fact that with a smaller wheel diameter the speedometer twists the real mileage and for the odometer to show 100 km, you will actually need to drive a shorter distance, and with a larger diameter you need to drive in reality a distance exceeding 100 km from here and increased consumption comes out.
If anyone has a desire to check, drive the distance from home to work on the same wheels, change the car and drive along the same path on these wheels (exactly along the same path) and compare the odometer readings, in my opinion the readings will be different.
Once again, I ask if something is wrong, if I am wrong, correct it, but do not criticize, I am not yet experienced.
Thanks to all!
"We all know from childhood that this and that is impossible, but there is always an ignorant who does not believe in it. He makes discoveries." Einstein
The fact that the car consumes much more fuel than stated by the manufacturer: the standard driving cycles until recently differed greatly in terms of load from real operation. But sometimes the fault lies with the driver.
Wider tires of larger bore on heavier rims lead to a noticeable drop in dynamics and an increase in fuel consumption. Well, I don't need to explain how pressure and fuel consumption are related. It is not for nothing that in recent years TPMS pressure monitoring systems have become standard equipment on all machine classes. And in the US and Europe from 2014, all new passenger cars must be equipped with a similar system.
I will not open America: the higher the pressure in the wheel, the lower the fuel consumption. True, it does not decrease linearly; after a certain threshold, fuel consumption remains almost unchanged. On the other hand, the negative phenomena associated with pumping are becoming more and more noticeable. And this is not only a loss of comfort, but also a deterioration in the grip of the tire, and a general deterioration in handling due to a violation of the frequency characteristics of the tire-suspension ligament.
For this reason, tires have a recommended pressure, which the manufacturer always indicates in the documentation. Typically, for basic tires, the data can be found on the information decals on the body. The optimal pressure indicated on the decals is determined by experiment and depends on the characteristics of a particular tire model. Exceeding it without understanding the processes occurring with the tire is not worth it.
An increase in the contact area of \u200b\u200bthe tire with the road surface is usually associated with an increase in the width of the tire. But an increase in the outer diameter is also a fairly effective measure. And this is understandable: the larger the outer diameter, the larger the contact patch. Unfortunately, the large wheel also has disadvantages, first of all - the increased mass of the tire and rim.
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In practice, fuel efficiency and grip do not mix well in a single tire model. To achieve the lowest fuel consumption, a separate line of ContiEcoContact rubber is produced. It is distinguished by lower rolling resistance, lower weight, and lower resource. And, of course, maximum efficiency, even when compared to the ContiPremiumContact 6.
But in the line of tires of quite classic dimensions and appearance, there is also one completely new model. Don't be surprised, its dimension is 195/55 R20. I did not describe, the landing diameter is exactly 20 inches, and the tire width is 195 mm.
Remember what I wrote above about the relationship between the working pressure of a tire, its width and diameter, and fuel consumption and grip? It looks like engineers have found a new way to reduce fuel consumption. This path is not easy, it includes several solutions at once.
First, the new tire material makes the wheel grip more efficient.
Secondly, the large outer diameter of the wheel improves traction even more. But the width of the tire has been reduced to reduce rolling resistance.
And most importantly, don't forget about pressure! The developed tread material allows you to maintain grip with a higher internal tire pressure, which, as you already understood, gives a benefit in economy.
30.10.2015
A vehicle's fuel efficiency depends on many factors. One of the most important properties of tires is the fuel consumed while driving. The tire's fuel rating is placed on the tire labels. The rating is based on the rolling resistance of a given tire on a scale from A (best efficiency) to G (worst efficiency).
Rolling resistance tells us how strong the friction is at the wheel-ground interface. The greatest influence on friction has the properties of the tire, which undergoes deformation during driving. This results in energy loss in the form of heat. Minimal rolling resistance, lower energy consumption. The result is minimal fuel consumption. The rolling resistance is investigated on the basis of strictly defined principles on specially adapted machines. Tests are carried out on a drum at a uniform load and speed that reflects normal operating conditions at temperatures close to 25 degrees Celsius. Results are expressed in kilograms per tonne.
The greatest influence on the rolling resistance is, therefore, mainly the same tires. Rolling resistance mainly depends on the design of the tire, used in the mixture of rubber components, the tire's internal pressure, its technical condition, and the operating conditions. Lightweight tires have lower rolling resistance, which are characterized by fewer and thicker elements. In addition, the shape of the tire-to-road contact surface is important, as well as the shape and design of the tread. The increased stiffness of the tire makes it less deformable. This results in lower rolling resistance, which leads to lower fuel consumption.
All major tire manufacturers are constantly working on new technologies to reduce rolling resistance. One of the many examples of innovative solutions can be a mixture created by the Japanese concern Yokohama. It uses compounds of polymer and finely dispersed silicon dioxide with the addition of essential oils from orange peel. The goal of Japanese engineers is to find environmentally friendly solutions that will reduce the proportion of petroleum products in tire production. The result is a compound that reduces rolling resistance by 20 percent compared to a conventional compound, without sacrificing adequate grip and wear resistance.
High rolling resistance can be caused by insufficient tire pressure. It increases sagging and less stability of the tread blocks in contact with the road. Pressure below 1 bar from the recommended level will cause more rolling resistance by about 30 percent. This results in an increase in fuel consumption. Tire manufacturers use various methods to prevent air ingress. Yokohama uses a special paper-thin insert. It is made of elastic rubber and original plastic, which reduces air loss by 36 percent.
The difference in resistance between the highest and the lowest energy efficiency class is 5.5 kg / t. In practice, a class A tire, especially on long routes, heats up less. This results in lower fuel consumption, even up to 7.5 percent. In recalculation, this is about 6 liters of fuel for every 1000 km. However, it should not be forgotten that fuel efficiency is also influenced by vehicle parameters: body type, engine size, air conditioning use and even driving style. Fuel consumption (with tires of the same class) may vary due to these factors. Provided that an average driver drives an average of 35 thousand kilometers a year, he can save up to 200 liters of fuel.
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Volga's donors are Volvo 940 and Toyota 2JZ-GE.
It all started with the fact that a young guy bought a used GAZ-24 and first put it in order. Having driven the car for three years, the young car owner decided to independently tune his car in order to turn it into a more modern design.
The tuning project started with the replacement of the suspension and the replacement of the rear part of the Volga with the rear of the Volvo 940. The hood was also redesigned. Then it was the turn to change the engine under the hood. The owner of the car placed a 230-horsepower 3-liter engine from Toyota 2JZ-GE in place of the old engine, paired with an automatic transmission from the "Japanese".
After changing the technical part, the motorist came to grips with body work. The roof was lowered, like American muscle cars of the 70s, then the 4-door sedan turned into a 2-door coupe. A new body kit appeared in the form of custom bumpers and wheel arches, new optics and other body elements that the author of the project developed himself.
And, finally, the rims were replaced, after which the Volga started to play with new colors.
The opinions of netizens about the tuning project were divided. Some liked the result very much, others noted that the car still looks like a "collective farm", that you don't do it with it
The experts told about the correct actions of the driver when the traffic police officer asks: “Why are we breaking”?
On the territory of the Russian Federation one can often come across a phrase popular among inspectors: “Why are we violating”? However, it does not always mean that the driver really violated any law.
In case of a really committed violation, the traffic police officer draws up a special protocol, in which all information about the composition of the violation, the date, as well as the signatures of both parties, including the full agreement with the described circumstances of the crime, are entered. The latter is done so that the driver cannot later appeal the fact or absence of a violation in court.
But Russian motorists rarely start disputes with traffic police officers, so they agree to sign and pay for everything. At the same time, most of the “recorded violations” were not actually committed, so it is quite possible to appeal them in court. Basically, drivers agree to sign protocols after a minor psychic attack, which is often practiced by patrol officers. For example, a standard question: “Why are we breaking”?
This very question immediately puts the motorist in an uncomfortable position, who begins to think what he managed to violate, but in the end everything ends with a search for excuses, even if there was no violation.
Selling Korean-made Hyundai Solaris cars in the secondary market, motorists can gain up to 90% of the original price. In the premium segment, the Volvo V40 Cross Country becomes the leader, with sellers receiving 88% of the resale. Owners of the Korean Kia Soul car can also expect to benefit from the sale, receiving 87% of the original price.
The three leaders are closed by the Japanese crossover Mazda CX-5, the owners of which, having decided to sell the car, can get 86.5% of the starting price by selling the car in the secondary market.
The most disadvantageous in terms of resale are: BMW, VAZ "UAZ" and Peugeot, as they quickly lose in price, and, accordingly, sell them on the secondary market is much cheaper in comparison with the original price.
22.11.2015
Many drivers strive to fit the widest tires with large rims to improve the visual appearance of the car. However, few people think about the direct effect of tires on fuel consumption during operation. The main subject of disagreement is the tire rim and profile width. Today, all drivers are divided into two directly opposite camps. One part of drivers is trying unsuccessfully to prove to others that by purchasing smaller tires they have been able to significantly increase the fuel efficiency of their car.
Arguments of the defenders of the theory
Advocates of the theory offer arguments that much more force is needed to spin larger wheels. Accordingly, for the processes of starting movement and acceleration, an increased amount of gasoline will be required, however, the average speed will increase by 10-15 km / h (which will play into the hands of lovers of an active driving style). Despite the objectivity of the data, it is extremely difficult to calculate the exact percentage of increased fuel losses, since it depends on a number of very diverse factors (disk weight, technical condition of the machine, etc.).
The most ardent defenders of the theory are sure that fuel consumption increases non-linearly, therefore it directly depends on the selected speed mode. In the process of driving at low speeds, the increased fuel consumption will not be significant, but with the development of speeds above 40-50 km / h, its consumption will increase sharply.
Opponents' arguments
In an attempt to find out the truth about the effect of wheel size on fuel consumption, most experts resort to knowledge of physics. Due to this, there is a theory that low fuel losses will cause an increased number of engine revolutions, because the work will be performed equally. Gasoline consumption will mainly depend directly on the mass of the vehicle and aerodynamic braking.
The existing "theory of the car" implies the presence of a special formula, which can be used to calculate the directional consumption of gasoline Qs, which allows us to neglect the dynamic values \u200b\u200bof the radius. In this case, the used tire profile height must be taken into account: the higher the profile height, the greater the fuel consumption.
Profile width and its role in fuel efficiency
Probably everyone understands that wheels with a wider profile require more fuel, because the weight of such a wheel will be large. In addition to this, the engine will require increased effort to move the machine. In addition to weight, the contact patch area usually increases, and with it rolling resistance and acoustic noise.