# Bigger Tires and Fuel Mileage



## Jungda99 (Nov 17, 2006)

Hello,

I have a 06 Silverado Diesel 2500HD which will need tires pretty soon. It currently has 245/70/R16s which just look cheezy.

I have always had 265s BFGs on my half tons which was the stock size and have been extremly happy with them.

My question is I am thinking about putting R16s 265s or even 285s on but I am curious how much it will affect the fuel milage. I know I will need to reprogram the computer to match the tire size so the MPH and shift points are correct.

Going 60MPG I currently get a little over 20.6MPG and going 74MPH I get about 18.4 MPG

I have heard rumours about the 6 liter losing 2MPG when bumping to the 285s.

Any information would be much appreciated. Thanks


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## bretts (Feb 24, 2004)

I drive an 08' 3/4 ton chevy, it came with 245's on it, not sure why, just looked ridicilious, I was getting 14 mpg avg with those tires, I switched to the 285's & cranked up the front end, I'm currenty getting 10.2 mpg/avg. It definitely drops off once you put the 285's on, I can say I love having the ground clearance, but you will definitely notice a difference in gas mileage.


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## ndgooseslayer (Jul 26, 2007)

I would say you are doing pretty dang good to be getting the mileage you are if it's on a consistent basis.

On my superduty, factory was 265-75-16. About a year ago I went up to 285s and actually saw a gain of about 1.5 mpgs average over about 10-12 fillings (I put on a fair amount of miles, so i keep track of this stuff). The rpms run alittle lower (1800 rpm) at 70 mph (supposedly the sweet spot for fuel economy on the powerstroke). I'm actually tempted on my next set to jump up to alittle taller tire yet.


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## Jungda99 (Nov 17, 2006)

Wow I didn't think it would drop the mileage that much.

I think they put on the 245s so they can get a higher payload capacity and towing capacity and maintain required specs.

The 245s do look out of place on a giant heavy duty truck

Thanks for the info

Anyone else have any feedback?


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## Jungda99 (Nov 17, 2006)

ndgooseslayer said:


> I would say you are doing pretty dang good to be getting the mileage you are if it's on a consistent basis.
> 
> On my superduty, factory was 265-75-16. About a year ago I went up to 285s and actually saw a gain of about 1.5 mpgs average over about 10-12 fillings (I put on a fair amount of miles, so i keep track of this stuff). The rpms run alittle lower (1800 rpm) at 70 mph (supposedly the sweet spot for fuel economy on the powerstroke). I'm actually tempted on my next set to jump up to alittle taller tire yet.


increase in mileage? Now thats what I like to hear..haha

Yeah it is pretty consistant. I have had it since the first week in september and have put on 8,000 miles pretty much all on long trips for hunting ect. I am extremly religous about checking the mileage on all of my vehicles

The key for my truck is keeping it below 2000RPM but like you said 1800 gets about the best MPG. The "in town" mileage is much worse as the stop and go kills the mileage. In town I get around 14-15 if I am easy on it.


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## dogdonthunt (Nov 10, 2005)

as in 'bigger' are you refering to wider? because the three digit number you are talking about refers to the width.... and if you are only going wider you dont have to adjust your speedometer... its only if you go with a taller of smaller tire size when you have to adjust that.... heres a link for you

http://www.tirerack.com/tires/tiretech/ ... ?techid=46

hope it helps


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## Jungda99 (Nov 17, 2006)

dogdonthunt said:


> as in 'bigger' are you refering to wider? because the three digit number you are talking about refers to the width.... and if you are only going wider you dont have to adjust your speedometer... its only if you go with a taller of smaller tire size when you have to adjust that.... heres a link for you
> 
> http://www.tirerack.com/tires/tiretech/ ... ?techid=46
> 
> hope it helps


you are correct...I want to go wider and taller. Probably 265s but I am unsure how much taller. I don't want to go huge or anything like that just something that fits the truck a bit better.

Any recomendations?


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## ndgooseslayer (Jul 26, 2007)

dogdonthunt said:


> as in 'bigger' are you refering to wider? because the three digit number you are talking about refers to the width.... and if you are only going wider you dont have to adjust your speedometer... its only if you go with a taller of smaller tire size when you have to adjust that.... heres a link for you
> 
> http://www.tirerack.com/tires/tiretech/ ... ?techid=46
> 
> hope it helps


Keep in mind the aspect ratio is a percentage of the tread width, so a 285/75-16 will be a bit taller than a 265/75-16. I did go about 2" taller when i changed sizes.


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## hunt4P&amp;Y (Sep 23, 2004)

Pretty sure on most diesel's when you go bigger you get better milage... to a point as they have the power and torque to drop RPM's with the lower revolution's per minute.. but on 6.0 gassers they don't quite have the torque and power to lower the RPM's with more meat.

I have no idea why they put those damn rubber bands on the new pickups. Just got a new Cummins, and the thing looks stupid gotta order some 33's or 35's soon!


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## Jungda99 (Nov 17, 2006)

Well i think I might go with 26575R16s. Looks like they are 31.8" tall and from what i have read anything under 32" will fit the truck without and modifications. I would think they would look better than the factory "rubber bands" huh???


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## hunt4P&amp;Y (Sep 23, 2004)

Jungda99 said:


> Well i think I might go with 26575R16s. Looks like they are 31.8" tall and from what i have read anything under 32" will fit the truck without and modifications. I would think they would look better than the factory "rubber bands" huh???


For sure! What brand are you going with?


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## Jungda99 (Nov 17, 2006)

hunt4P&Y said:


> Jungda99 said:
> 
> 
> > Well i think I might go with 26575R16s. Looks like they are 31.8" tall and from what i have read anything under 32" will fit the truck without and modifications. I would think they would look better than the factory "rubber bands" huh???
> ...


BFG AT KOs I have had them on my past two trucks and love them. Granted I havn't tried anything else other than the factory tires but they havn't let me down yet.

you have any recomendations?


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## hunt4P&amp;Y (Sep 23, 2004)

Jungda99 said:


> hunt4P&Y said:
> 
> 
> > Jungda99 said:
> ...


I run Nokian Vativa MT's They are decent tires. Get you through some crap and are good on ice.

Have you had alot of problems with wear on those? I know a few guys that go though those like mad.


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## Jungda99 (Nov 17, 2006)

50,000 everytime. weather that is good or bad...not sure


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## hunt4P&amp;Y (Sep 23, 2004)

Jungda99 said:


> 50,000 everytime. weather that is good or bad...not sure


Thats good.

I am pretty tough on tires, weight, spinning, so on.. I usually get about 30k or so.


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## cut'em (Oct 23, 2004)

Stay away from the BFG Mud terrians they look badass but they wear like crap I've got about 15k on my set of 37's and I don't think I'll make it through the winter with these. Talk about mileage believe it or not my highway mileage didn't drop when I installed these on my 07 F250 diesel still got 14.5 cruising at 2000 rpms. It wasn't until I brought my truck in for warrenty that the mileage dropped I know they re-programed my ficm (fuel injection control module) Ford calls it an update and they wont go backwards and un-program it. anyways I now see at best 9-10.5 mpg. If anyone is running a ford and seen this dramitic drop in mpg's after a service it's not their imagination The dealer wont tell you they added the update, Ford simply toned down the program to get these trucks through the warrenty period :******:


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## dogdonthunt (Nov 10, 2005)

any mud terrain tire isnt gonna get you the milage you want (wear milage)... its a soft tire to begin with... try the BFG AT's .... when they are first new they tend to throw alot of rocks though...


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## GKBassplayer (Feb 19, 2008)

Ive got 35,000 on my BFG AT's and by the looks of it i probably have another 10,000 left, I like them just fine. I think I am going to go up a size next time tho


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## cut'em (Oct 23, 2004)

Ya know it's crazy, we used to run the all terrains 25 years ago and I still remember the trucks wearing out before the tires. Of course we were running **** box trucks, but we'd always take the BFG's with us onto the next truck. The only thing I didn't like about them is they seamed alittle slippery in wet conditions. Has that changed?


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## hunt4P&amp;Y (Sep 23, 2004)

It has alot to do with the weight of the pickup... having a Diesel pickup weighing much more then a gasser with a ton more torque is hard on all tires. But the BFG's seem to be even worse. Must just be the compound.


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## MossyMO (Feb 12, 2004)

I am on my 5th or 6th set of BFG AT's, just upgraded a week and a half ago; obviously I am quite happy with them. I agree with dogdonthunt, they do like to pick up and throw rocks when new though.....

My F150 came stock with 215/70/16's and I have been running 285/75/16's it for the last 90K. I am sure it dropped my milege some, I consider myself thrifty but the pickup looks so much better than when I purchased it.


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## Goose Guy350 (Nov 29, 2004)

I read an article years ago where they put several different brands and models of tires of the same size on one pickup and checked the mileage. Some tires just devastated the gas mileage while some made it better than factory. I don't remember all the brands and sizes they tried but if I remember right the BFG AT rated very high if not the best for fuel economy. Wish someone would go through and do another test like this with all the new tires out there.


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## dogdonthunt (Nov 10, 2005)

sounds like a job for Mythbusters


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## coyote_buster (Mar 11, 2007)

if your not going wider and just taller it should help your mileage with the exceptions of going to a more aggresive tire, going wider maybe, lots of stop and go, i stepped up from a 235 75 r15 to a 31 10.50 and it kept the same mileage once in a while a mile or two better and i went to a much more aggresive tread, this is going gravel roads about 7 miles to town


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