Ok, please don't blast me. I have searched, but have not found answer. I have a 2007 megacab with 5.7 hemi. I have the stock michelin 265 70 17 tires and want to change to nitto terra grapplers in 285 70 17. I currently average around 13-14 mpg on city/hiway. Any idea on how much mileage will suffer with bigger tires, 1-2 mpg, less or more. What about performance, any problem with these bigger tires and hemi or what if I went with a 295. Yes I know this is not a gas mizzer, but I dont want to drop 3 mpg.

thank you

 

you could always change your gears if you want bigger tires . but i dont think the difference in mpg is going to be that different. i upgraded from 265-70 r17 to 285-70 and there was no noticible difference in my mpg. a tuner will help along with a cai.

 

I dont think it will that much difference at all either. Thats not a radical change IMO. I agree with gears because I hear Megas suck when it comes to MPG already anyway.

 

no difference in MPG to speak of!

 

Not much of a difference due to size. Now a more aggressive tire will drop you a mpg or two over a soccer mom type tire.

Your overhead will show you getting worse mileage than what you are actually getting, unless you recalibrate your speedo. But in reality, you wont be that bad...

 

I have 285/70 R17's on my '05 Power wagon. 4.56 gears and get 12-14 mpg.

 

CAI wont do anything for mpgs.

 

Thanks for the replys. Sounds like a 285 wont do much damage to my mileage. I may move up to a 33" tire. I want something that looks better than the puny stock tires without killing mileage and performance to much. I notice a lot of people have 33s and 35s, but I would guess the 35s would be a big hit.

 

i think if you bought a mega cab, mpg wasnt a high priority.