Best tire for looks and MPG

gotsteam · January 17, 2012

New to this site, and am finding a lot of good information on here.

I have a 2007 GMT-900 GMC Sierra. It has the 5.3l with 3.73's. Currently I am running the stock size 245/70/17's, but added a leveling kit and wanted to go to a larger size tire. I want to run 285/70/17's, but how much will my MPG suffer? Currently getting around 14 city, and between 18-21 highway. I am happy with the gas mileage right now, but the stock tires are too small. Looking at getting BFG A/T tires.

Anybody with a similar set up (5.3l/3.73's, going from 245's to 285's)? How much loss could be expected (taking into account speedometer error)?

I have spent hours looking using the search button, and looking at some great looking trucks. Obviously there will be a loss, not looking at driving a prius, but just happy with my current MPG and don't want to suffer much. Any feedback would be greatly appreciated.

Thanks!

Big Whiskey · January 17, 2012

You can expect a 2-4 mpg decrease, depending on your drivng habits. BFG's are great tires, but they're heavy. And, if you want the white letters, your only option in a 285/70/17 is a Load Range E tire, which is a 10-ply. The black walls are available in a Load Range D, which is an 8-ply. If you're too concerned with the MPG drop, a few companies make a 275/70/17 tire in the standard P-Rated, 4-ply setup...or in a LT rated, 6-ply (Load range C). Those wouldn't be quite as big as a 285, but they're close...and could save some weight. The price of cool isn't cheap, lol.

dirtfan21 · January 17, 2012

I was going to say the exact same thing as above. If you want something a larger but will still get decent mpg's then stick with a 275/70/17. I ran a 275/65/18 Revo 2 on my past '07 with a 2" RC level and the look was a noticable difference from stock. Nothing beats the look of a 285 with a level but sometimes you have to choose between looks and function. I got tired of function and lifted my old truck, stuck the largest 285's I could under it and then got 12-15 mpg's.

If you are getting 14 in town expect 12 or less on 285's, highway at 18-21 then expect 15-18 or less. That is right around the loss I experienced.

FYI Cooper, Goodyear, Mastercraft, BF Goodrich, all make 275/70/17's if you are interested.

Big Whiskey · January 18, 2012

Great minds think alike!

dirtfan21 · January 18, 2012

It may be the blind leading the blind too.

jdubub · January 18, 2012

I just sold my 285/65/18s due to mileage decrease. They weighed 22lbs. over my stock 265/65/18s because they were 10 ply. I went from 18.2 mpg on AVG to 14.3. I didn't want to dish out all of the extra fuel over the life of the tires, so I went back with a cooper 33" AT 4ply that has a mileage warranty and only weighs 1.4lbs. heavier over my stock tires....... got my mileage back!

Moral of the story- If you want to keep most of your mileage, stick with a 4ply or at most a 6ply.

gotsteam · January 18, 2012

Hey Guys, Thanks for the help. How much worse would you imagine a 285 would get me for mileage then the 275? Being I have 245's right now, even 265's would probably look better, but I imagine still really small on my truck?

Jdubub, so you experienced that it is the weight as the main factor in your gas mileage, more so then the size? A 33" tire is actually probably slightly bigger than a 285, but because it weighed less, you got your mileage back? Are your new tires P Rated or LT?

Thanks again!

jdubub · January 18, 2012

Hey Guys, Thanks for the help. How much worse would you imagine a 285 would get me for mileage then the 275?(It all depends on what ply= weight) Being I have 245's right now, even 265's would probably look better, but I imagine still really small on my truck? (I have 265/70/18s on now and while they are not my ideal width they still look damn good and function way better than the havier 285s)

Jdubub, so you experienced that it is the weight as the main factor in your gas mileage, more so then the size? (In my case, yes sir ) A 33" tire is actually probably slightly bigger than a 285, (My 285s were 32.9 in diameter and my 265/70/18s are 32.8 in diameter, so I was rounding up ) but because it weighed less, you got your mileage back? (Correct) Are your new tires P Rated or LT? (P rated, they are lighter to keep my mileage)

Thanks again!

A lot of the exact diameters, width, weight etc. are on the tire manufacturers websites. Sometimes they are not, but with a 5 minute phone call to their customer service number they can tell you. I had to call a few to find the perfect tire to gain my mileage back, along with comparing tread and mileage warranty. My current coopers have a 55k mile warranty

Ryan00TJ · January 21, 2012

I just went from stock LT C rated 245/70/17's to 275/65/18's P rated Cooper AT3's. Stock ride height. Justin @ BB has retuned my ECM for the the size change. Averaged 17.5-18 MPG before with winter blend fuel and now @ 15.8-16.3 MPG after. Same drive to work every day.

The 275/65/18 is a 32"x11" wide tire vs the stock 245/70/17 at 30.5"x10".

Silverado4x4 · January 21, 2012

You people say that your loosing mileage on oversize tires are you taking into account that your speedometer and odometer is now off and reading slower in speed and less miles on the odometer per miles traveled on your truck? So unless you get the speedometer fixed you wont see proper mpg's, it will always show a loss. yes it will drop some but not what some of you are saying.

jdubub · January 21, 2012

Mine is tuned. Tire size is always changed and mileage is correct.

dirtfan21 · January 23, 2012

My truck's BlackBear accounted for the tire size change also. My 285's were 72 lbs a tire and my stockers were around 43, the size was 32.8 by 11.9. So yes, I did lose all the milleage I reported.

AgDoctor · January 26, 2012

I went to a 275/70-18 BFG ATKO, and have had 2 sets of this size. They will definitely drop you a good 2 mpg if not a little more. I had a set of the same BFG ATKO in a 285/65-18 and the results were about the same. Maybe had a little more pep with the 285's, even though they were supposedly slightly heavier. I avg about 14 or better on these and got about 17 on the stockers. I would love more gas mileage but honestly if you can afford on of these trucks an extra few bucks a month in fuel is the least of my worries. I tried a set of slightly larger than stock(265/70-18) Coopers and the mileage still dropped and they were C range and looked too sissy for my tatstes. I would rather them look good and perform well that make the whole truck look like crap and still perform well. I have taken a set of highway tread tires deep into to mud on one of my company trucks and though it requires alot more go-pedal they will go most places a set of AT tires will with enough speed. I said that to say this, if you are getting a different tire for pure offroad performance, an AT tire usually is more dependable rather than actually justifiable. I put about 30,000 miles a year on a pickup and alot of those miles are in tuff spots( we do soil surveying and GPS mapping), so I have had or tried several different tires. I seen about the same mileage as these BFG's(ATKO) with a set of Cooper Disvoverer STT's in a 275/70-18, they are just louder than I would want to deal with on long trips.