I switched wheels from the stock 15" sawblades (205/65-15) to se rims for a1997 Max. On the se rims I put on some Kuhmo 225-55-16's because they seemed like a decent tire for the price at America's Tire(They didn't have the 215/55-16's in this tire). The 225's are slightly larger and will effect my speedo by 1.0%(meaning at 60mph speedo reading I am actually going 60.6mph)

Will these larger wheels and tires effect my mileage negatively? Seems like they have to me by 2mpg or am I just worrying about nothing?

Thanks,

Fro

 

Yes, heavier and larger wheels/tires will hurt mileage slightly. Also, the wider tires should give better grip and therefore increase friction a bit, which also hurts mileage.

 

op, 215 vs225 means your tires are 10mm wider. why does this affect speedo as only diameter that makes the wheel spin faster or slower should

you will not notice the difference in mpg... i switched from 15" steelies to 16 se rims and it seems the same

 

now I would love to know how you know that you are going 60.6

 

Do you understand how tire sizes work? 205/65 has a slightly different overall diameter than 225/55. The first number is the width in mm, the second number is the ratio of width to sidewall height. You can check a tire size calculator to find out the difference. In this case, 205/65/15 has an OD of 25.49 inches and 225/65/16 has an OD of 25.74 inches, which as the OP said is difference of about 1%.

 

its just calculations as far as i see.

 

Which means in the real world you will be going............the same speed. Oh wait, let me guess. Nissan had different speedo calibrations for cars that shipped with 15 in rims vs 16 in rims.

 

Think I have it figured out, I weighed the SE rim with the 225-55-16 tire on it on my digital scale(used to weigh humans) and it weighed 46.5lbs. I then weighed the 205-65-15 sawblade tire with tire on it 39.0lbs. Hmmmmm, makes sense my mileage is worse.

Now I want my sawblades back on my car and I have a set of SE wheels with tires on them with almost brand new tires (1500miles) on them.

Wonder if America's tire will give me a good proration on the 225-55-16's if I buy some 205-65-15's. I will probably take a $100 hit on the deal I bet. Stupid me.

Fro

 

My honeycombs weigh more than my LW 17's.