Category: Automakers

Tumbleweed

2023

Table of contents:

Video: Tumbleweed
Video: The Trouble With Tumbleweed 2023, February
Tumbleweed
Tumbleweed
Anonim

Well, we are not ready to change bicycles yet, and the climate is not the same, so we will try to reduce the load on the wallet with less radical means. Our new section is dedicated to the savings reserves.

COMFORT FEE

The smoothness provided by car tires has a flip side: part of the useful energy is spent on heating them. Many people underestimate the effect of tires on fuel consumption or believe that it is noticeable only at high speeds. But on the highway, the main enemy is aerodynamic losses. But in a city where speeds are low, ceteris paribus it is tires that eat most of the fuel and eat a lot: by reducing tire rolling resistance by half, it is possible to save up to 20% of fuel.

FOR THOSE WHO UNDERSTAND

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The most radical solution is to use special tires with reduced rolling resistance. All leading manufacturers produce them: Michelin, Continental, Bridgestone, Pirelli. For comparison: the rolling resistance of most low-cost passenger tires is in the range of 12–15 kgf (traction required for driving) per ton (vehicle weight), good freight - 8–10 kgf / tf, and imported “eco” tires of the latest generation up to 6.5 - twice (!) lower than that of models of twenty years ago.

The designers of these tires have to solve, it seems, mutually exclusive tasks. On the one hand, it is necessary to reduce rolling resistance, so the tire must be elastic, with minimal hysteresis (permanent deformation). On the other hand, without hysteresis it is not possible to provide grip properties - the tire must cling, “stick” to the road. It is possible to reconcile opposites by achieving different tire behavior depending on the oscillation frequency: at a low frequency (in the tire volume) the hysteresis is small - the tire elastically fulfills large irregularities, and at a high frequency (on the surface) it is sufficient for reliable adhesion to the road surface.

And yet “environmentally friendly” tires are not for racing; perhaps they will disappoint the driver, accustomed to active driving. But the lean one will be pleased - not only with fuel economy, but also with wear resistance. On average, the price difference between a set of 14-inch domestic tires and imported "eco" pays for itself in just 10-15 thousand kilometers!

COMPLEX INTEREST

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Significantly affects fuel consumption and tire pressure. The loss of only 0.3 bar increases the rolling resistance by 6%, and with a shortage of 1 bar (outwardly inconspicuous), it increases already by 30%. Add to this the accelerated (three times!) Tire wear - the assessment of pressure on the eye is a little expensive!

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An increase in pressure against the norm, on the contrary, reduces fuel consumption. The increase of 10% practically does not affect the tire resource and passenger comfort. With a 20 percent pressure increase, the car becomes noticeably tougher, reacts more sharply to steering actions. On slippery, wet surfaces, this is sometimes dangerous. But the resource of pumped tires is reduced slightly - by only 10% (half as much as under-pumping). However, in Russian conditions it can even increase, because pumped tires are better protected from breakdowns.

However, often car manufacturers themselves indicate the pressure range depending on speed and load, and at speeds above 160 km / h they recommend raising the pressure, for example, from 2.2 to 2.7 bar. We note this fact and we consider the increase of 20–22% to be the maximum allowable. Of course, the pressure should not exceed the limit indicated on the tire. By increasing the pressure, it is possible to reduce fuel consumption by 3-5%, but only on a more or less smooth road. At the side of the road, shock absorbers will take over part of the tire operation.

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