The time has come for new tires, and I am debating whether to stay with OEM sizes or go bigger to 245 fronts and 275 rears. I began wondering whether wider tires decrease fuel efficiency. Any advice/knowledge/etc.? Thanks!

 

Assuming your rears will be 275/30, you will have a smaller diameter in the rear versus the stock 255/35's. So yes, you'll lose a little bit of gas mileage.

 

I'm running 285s and 245s and have noticed no difference. To the OP, why not go with 285/30s in back there are closer in OD to the 255/35s and will work on stock wheels?

Lou

 

In hind sight, I should have gone with 285/30's instead of my 275/30's. The selection of 285/30's is limited though.

 

Hi Lou!
As mugenh22a4 stated, 285s are limited in selection. I was referring to the Michelin SSs initially, but I'm also considering the Conti Extreme Contact DWs which are available in 285s. I'm also considering the Vredestein Ultrac Sessantas, but those are limited at 275 as well. Any of those you'd prefer? I've read all over this place, and I don't think I could go wrong with any of the 3.

 

^^^I'm running the Extreme DW and luv 'em. I have a thread on them.

Lou

 

Width no, diameter yes.

The only effect width would have is if it increased the weight of the wheel. Smaller diameter equals more rotation to equal one rotation of a larger size... but it's not like you can put wagon wheels on a car and it will get 60 mpg. LOL

 

i am going with Continentals as well. if price is your concern i would get the vredestein. if you want the best performance then michelins, the continentals aren't bad either. for better tread life, i would pick continentals. its up to you to decide which ones suits you best.

 

Thanks to everyone!

 

Sorry if this is hijacking the thread, but do any of you think running a smaller profile tire (275/30 instead of 255/40) is bad for the rim incase I hit a pothole? In NY our potholes are like giant craters in the road

 

I don't know about "bad" but it definitely sounds "riskier". I mean, common sense would tell me that you have less "cushion" w/ a smaller profile, so that's where I would believe it would be more dangerous. Sorry about the crappy roads!

 

I've often read that tire width greatly affects a car's drag. If that is the case, then I could see wider tires having some negative impact on gas mileage, perhaps more relevant at higher speeds like highway cruising speeds. Whether that's noticeable or not is another matter.

 

Check out the LS430 how skinny it is and how comfy it is
Different needs have different needs

 

Yes wider tire does affect MPG doe to a higher "rolling" resistance. If you notice drag cars have very skinny tires on the front to reduce weight and rolling resistance to improve times.

As of crazy tire sizes for the car IMO is not going to do you any good mainly because front rim is 8 inches wide and rear is 9. Widest you can go is 235 front and 265 rear not to upset the ratio of the tread width to the rim. Otherwise wider sizes would fit but will adversely affect the handling which is the opposite of what you are trying to accomplish with wider tires.

Keep in mind if you go with 235/265 combo then Michelin for example doesnt make 235/40/19 front tire so you would need to go lower sidewalls of 35 which will offset your speedometer/odometer calibration since the radius of the tire WILL decrease from what you had there stock. Pretty much you cant win but keep stock tire sizes for stock rims unless you upgrade rims as well. If you do decide to get new rims then you should go with 245/40/19 fronts and either 265/35/19 or 275/35/19 rear.

There is a bunch of science involved into choosing correct sizes and not as easy as just "will it fit or rub" issue.

 

That's your OPINION and your OPINION only

Lou