i went from a stock pirelli 275/55/r20 all terrain to a nitto 285/55/r20 or a cooper zeon 275/60/r20 all terrain? i went to a 285/55/r20 on my toyota when i had it and it KILLED my gas mileage.

 

how bad was it when you say killed it? I would bet your probably looking somewhere around 12-14 on an f150 with that size, however I don't know. Plenty here probably have that size to help you out though.

 

i was barely getting 10 miles to the gallon towing a 5x8 utility trailer with the toyota and normally only got about 12.5 miles to the gallon otherwise. i would barely get 270 miles on a tank of gas(without any extra weight). towing the trailer i'd be lucky to get 220 miles on a tank haha. WEAK....and the reason i traded for an F150. The older model toyota's just didn't have the power....and now i'm just turned off to the fact of a foreign truck. I had an 04 f150 back in the day and loved it...never should have sold it. now i'm driving a 2008 King Ranch 4x4 with 29k miles on it and already through the city i'm getting 14.5 miles to the gallon with a lot of stopping and going and 35mph zones. I just want to keep the decent gas mileage but i like a little more of an aggressive look with my tires so that is why i was looking at the coopers or the nitto's.

 

the question is are they aftermarket wheels. thats where it kills you. some are a lot heavier then stock wheels. You shouldnt notice much of anything. a 285/55/20. is like a 32.3 and the other is a 31.9 ish. You arent really gaining but a half inch wider and taller. I think stock fx4 tires are around 32" tire anyway.

 

mine are 32" anyway 2010 fx4. i also get anywhere from 14 to 17.5mpg

 

staying stock on the wheels and don't plan on aftermarket ones. so a 285 55 r20 nitto is 32.3 and the 275 60 r20 cooper is 31.9ish? i remember my wheels with the nittos on the toyota seemed REALLY heavy but they had the enkei wheels on it. Smokey are you running stock tires still?

 

I have the Cooper Zeons in 275/60/20 which is a 33" tire on OEM wheels. I normally get about 11-12 in town and 14-16 on the hwy. I also have a fiberglass cover and usually a hundred pounds or so of tools and stuff in the back so I am sure that cuts mine down some plus I also run a performance tune most of the time.

The 275/60/20 is only about an inch taller than your stock tires. I doubt you would see a huge loss with just that change.

 

the 275/60 is pretty much a 33" tire. I am still on stock wheels. I have aftermarkets which do kill my fuel mileage. The nitto tire id say is a little bit heavier then what comes with our trucks depending on what load rating you go with, but like mr ab42348934573498948257 said you wont notice it enough. The f150 isnt really known for its MPG's anyways. Hopefully that helps.
Just to give you an idea. my 20x9 KMC Hoss wheels with a 305/55/20 (33/12.60/20)Terra Grappler I get right at 12 -13 mpg all day long unless I tow something of course more then a small utility trailer.

 

275/55/20 is your 31.9 ish.
any tire you can convert. take the first number divide by 25.4(mm in an inch)= width of tire
multiply by the second number with a decimal in the front so....( .55 not 55) =sidewall height.
times that by two then add your wheel size (20)
There you have it.. hope that got you all screwed up!!

 

Another thing is to stay away from mud tires unless you need them or want them for something... In certain cases I have seen mud tires run up to nearly double the weight of a similar sized AT tire.

 

I used to run a 275/65/18 AT tire on stock rims and I was getting 19.5mpg highway. This was with custom performance tuning though.

 

thanks for the info...i sure wish cooper zeon ltz's came in 275/55/20. oh well....guess i'll have to decide.

 

after some research, it looks like cooper does have the 275/55/20's and i will probably go with them. hopefully my gas mileage doesn't take that much of a hit. i would like to stay around 14 in the city and 17 hwy. i wouldn't think it would change much since it's stock size on stock rims. unsure how much heavier a cooper is to a pirelli.

 

i think you will be just fine either way. the cooper is pretty much a street tire anyway. a little more aggressive, but to me not as aggressive as an allterrain. Id say if you google search tire weight you will find what you are looking for, but as far as that goes for what you are wanting in fuel mileage. You shouldnt have a problem.

 

thank you. looks like i'll only be adding 16 lbs with the cooper zeon ltz's over the stock pirelli ATR's. that definitely shouldn't make a huge difference. i could take a tool out of my toolbox and make up for that haha. the pirelli checks in at about 48 lbs a tire and the cooper 52 lbs.