Okay, so you’ve heard that under or over-inflated tires can affect your gas mileage. Did you know however that the size of your tires, their weight and the type of tread that they have all impact fuel efficiency as well?
A lot of things affect your gas mileage, including driving in cold weather, your speed, the amount of air drag on your vehicle, how well your engine is tuned and many other factors. It’s been calculated that just the combination of heavy braking and quick acceleration can decrease your mileage by almost 30% when traveling on the highway.
It’s also been calculated that the size of the tires you use, and their overall design, can have a 4% to 7% impact on your fuel economy. This differs slightly depending on whether you’re driving around town or on the highway. Also, while using larger tires will usually reduce fuel efficiency, the actual design and construction of your tires can sometimes offset the loss due to their larger size.
The impact that “rolling resistance” has on your fuel efficiency can be quite high. This is caused by the amount of friction or resistance that your tires cause when contacting the road and, since larger, heavier and wider tires contact the road more than smaller, lighter and thinner tires, they create more friction and thus decrease your fuel economy.
Interestingly, the tires used on race cars, called “slicks”, have no tread at all and are the best for fuel economy. The problem is that, without tread, they are also much more dangerous because they don’t “hold the road” well. In effect, your tire’s treads reduce your gas mileage but increase your car’s safety factor greatly and thus are a necessary evil.
There are tires that have been designed for better fuel efficiency however, and usually they have a tread that is shallower and they’re made of materials that generate less friction and thus less heat when driving. Usually the best tires for fuel efficiency are the ones that come “stock” with your car from the factory. The reason is that automobile manufacturers want to be able to get the highest miles per gallon possible when they undergo US Environmental Protection Agency tests.
What this means is that, when you go to replace the tires that came with your car, you should definitely ask the tire vendor you plan to use to give you advice on which tires have the best (i.e. lowest) rolling resistance.
Finally, as we mentioned earlier and as (hopefully) most of you know, properly inflating your tires is the best way to make sure that you get the highest gas mileage as well as protect your tires and make sure they last as long as possible. Every car owner should have a tire pressure gauge in their glove compartment to be able to check their tires at least once a week. The best time to do this is before you drive when the tires are cool.
It’s been calculated that you will save as much as 3% when driving on tires that have been properly inflated, which can amount to quite a bit of money if you do a lot of driving.
That’s interesting about race cars; I would have thought they would have more tread. I’m glad to hear that tires are another place where I can help my gas mileage. I knew that tire pressure had an effect, but I didn’t know about rolling resistance. I’ll have to keep that in mind when I get new tires (which I really need to do).
Jane its very much a balancing act. Tires with low rolling resistance and good economy generally have the least grip, therefore worse braking and acceleration. However that is not strictly always true. However when it comes to buying your tires (and money is not a concern) I think it is best to get a good brand set of tires. They may not provide the best economy or least road noise but they might save you from a crash which could cost a lot more $$
This article is very wrong about racing slick tyres. Slick tyres produced more grip in dry conditions. More grip is available because more rubber is touching the surface.The problem with slicks is they can’t disperse water without any tread.