jeneah

I usually get around 24-25 mpg combined city highway. Two fill ups ago I installed Dunlop Winter Sport M3 tires all around. At the end of that tank I had 23.6 mpg and at the end of the last tank, (which had the winters on the whole time) I only got 22.9 mpg. The guy at tirerack.com said I should not see any difference in gas mileage. I am wondering if it could be these tires causing my gas mileage to drop...and I am hoping it isn't a bigger problem. Can anyone help???

Thanks,
Jeff

LuvMyTSX

I have the same tires and see a 1-2 mpg drop also. Nothing to worry about.

Simba91102

Could be a couple of things at work here. You don't mention what size the tires are; if they're taller than the OE tires, you'll have actually traveled further than your odometer will indicate (and the longer you go between fillups, the more "hidden" miles accumulate). You also didn't describe how you are figuring your mileage (I've always found the trip odometer and amount to fill the most reliable; the MID if so equipped less so). I think you'll find that the factor most likely to result in a mileage drop is actually the weather though. I can average around 30 mpg on a tank at 70 degrees, while covering the same commute at 30 or 35 degrees will yield only 27-28. Perhaps you suffered the coincidence of installing your snow tires at the same time the weather changed.

jeneah

I figure my mileage every fill up by miles driven divided against gallons used. Also, I bought the car last winter so I don't think the change in the weather would be doing it. Thanks for the input though.

jswim99

Keep in mind some geographies change to a winter fuel mix for air quality reasons (more ethanol, I think). This gives me a 10% reduction in mileage every Nov. to March.