does new tires decrease gas milage?

Question

just put new tires on my truck--gas mileage has dropped 4mpg(at least). is this normal? or is something else likely going on?

I put the same size tires on...that I took off...Had kellys on and went to laramie but they are the same size

Answer 1

In many cases the Laramie brand is made by Kelly/Goodyear. The brand change is probably not the answer. The difference you may be experiencing is the difference in new Rev per Mile vs. Old Rev per Mile. Over time, worn tires will yield more "miles" on your odometer vs. "new" tires (revolutions per mile). The difference you are seeing is probably negligible.

Answer 2

I hate to break it to everyone who has responded so far but they are all wrong.

Yes tires can effect fuel mileage. Vehicle manufacturers frequently select OE tires for their vehicles based on their "rolling resistance". The more rolling resistance in the tire, the greater the impact on your fuel economy, though the differences can be quite small.

This is especially noticable on truck tires. Take the Michelin Cross Terrain for example - a popular OE and aftermarket replacement SUV tire. On most OE fitments the tread pattern is slightly different from those tires sold only as aftermarket replacements. The OE tires will have a "solid" shoulder thread block. This helps reduce rolling resistance and thus increase fuel mileage. Some of the aftermarket sizes have cross grooves in the shoulder that improves traction in rain or snow but can increase rolling resistance.

An extreme case is the Toyota Prius from a few years ago which came OE with a specially developed version of the Bridgestone RE92. Any Prius owner who has put a different replacement tire than this on the car will tell you their mileage took a nose-dive, as did their tire wear.

Unfortunately, there is no standard by which to compare the rolling resistance between tires. Consumer Reports does a rolling resistance test in their tire comparisons, but like so many aspects of their tire testing, I can not account for how valid it is.

Answer 3

Putting new tires on your vehicle can reduce gas mileage because you are now getting improved traction. However it should not be a four mile per gallon difference! Have you changed the tire size significantly? Bigger, beefier tires are harder for the engine to turn as well as your aerodynamic drag will increase both contributing to less G.P.M.

Answer 4

Yes When the A/C is on, there is a compressor that is driven from a drive belt on the engine. It takes a significant amount of power to drive this compressor. To make this extra power to drive the compressor, the engine must burn more fuel. Also, with most modern vehicles. When the outside air temperature is over 45 degrees Fahrenheit and you use the defroster to clear the fog from the windshield, the air conditioning compressor also runs. This is to make the windows clear faster. So in warm weather, only use the defrosters when needed and switch them off when the windows are clear to save fuel. Myth busters test was flawed. They did the test by adding fuel to the fuel tank. There was no way to know for certain the exact amount of fuel in the tank. They should have used an external tank with an exact known amount of fuel. Being off by even a small amount of fuel would skew the test results. Differences in vehicle weight including the driver would also skew the results. They used two different vehicles. No two vehicles will run exactly the same, even if they are the same model.

Answer 5

Could have low tire pressure, Or you had all terrain tires put on and you had regular street tires on it n before. The thicker tread on the all terrain tires can cause a fuel mileage loss because there is more resistance with the bigger treads.

Answer 6

Are tires same size, inflated properly, your speed the same, then not a problem of tires?

Better look into something else.

Answer 7

Max out your air pressure. It will tell you the max pressure on the tire it self. This will keep your tires rounder and help your mileage. Its what they do on the hybrids. to answer your question check your air pressure they may not have put enough air your new tires.

Answer 8

did you put the same size back on,different sizes will change rpm range on highway,larger tire need more power ,smaller tires need higher revs
maybe your driving harder now that you have new safe tires
also depending on were you are it has gotten a lot colder

Answer 9

If they are same size as OEM and aired up properly, the tires are not the problem.

Answer 10

if you put a new tires on, are they factory required size tires? if you put oversize tires on your vehicle, yes it will decrease your gas mileage.