Highway Tires vs AT Question

[14wntr]

Hello everyone,

My new to me GMC Sierra 5.3 4x4 came to me with Toyo Open Country Extreme 2 tires on it that are the following size. 285/55-20 The truck tire spec is for 275/55-20. This truck has no lift and they rub a bit in the turns.  How much could this be affecting my MPG? Would it be worth putting on Highway tires since that is where I spend 99.8 percent of the time? It seems these tires would have more rolling resistance than the correct size/HT instead of larger ATs. I took a 300 mile trip and saw 14.6 one way and 17.4 back. This seems low to me so I wanted to bring this up. My Toyo's are in great shape with very little wear so I could easily sell them. What to do...?

[Yondu]

I lost 3 with Duratracs and picked 1 back up with Cooper AT3 4S tires. 

[14GMCZ71]

I have the GY DuraTracs in the OEM size - P275/55R20.  I removed the front valance a while ago for various reasons.

 

Took about a 300 mile round trip on Interstate (70mph+) and truck got 18mpg.

[diyer2]

I live in Colorado mountains.

Drive dirt and paved roads.Occasional freeway when in the city.

Used to buy BF Goodrich K2, Cooper AT3.

Now have Cooper Star Fire.

Happy with them and liked the price.

Edited March 19, 2019 by diyer2

[crankman]

Yes since you are on pavement mostly heck yea Id run some good truck radial and I would bet you would see some improvement over an all terrain style. And go back to the OEM size.

Edited March 19, 2019 by crankman

[royalkangaroo]

15 hours ago, 14wntr said:

Hello everyone,

My new to me GMC Sierra 5.3 4x4 came to me with Toyo Open Country Extreme 2 tires on it that are the following size. 285/55-20 The truck tire spec is for 275/55-20. This truck has no lift and they rub a bit in the turns.  How much could this be affecting my MPG? Would it be worth putting on Highway tires since that is where I spend 99.8 percent of the time? It seems these tires would have more rolling resistance than the correct size/HT instead of larger ATs. I took a 300 mile trip and saw 14.6 one way and 17.4 back. This seems low to me so I wanted to bring this up. My Toyo's are in great shape with very little wear so I could easily sell them. What to do...?

I’m sure you’d see significant improvement.  I’ve been in the 20-25mpg range on long trips with my truck.  One thing to note is the Toyo 285/55/20s weigh 57 lbs according to their website.  Their P275/55/20 in the same style tire is 43 lbs.  That’s a decent difference in unsprung weight.

[14wntr]

1 hour ago, royalkangaroo said:

I’m sure you’d see significant improvement.  I’ve been in the 20-25mpg range on long trips with my truck.  One thing to note is the Toyo 285/55/20s weigh 57 lbs according to their website.  Their P275/55/20 in the same style tire is 43 lbs.  That’s a decent difference in unsprung weight.

I am sure this is the case! I was just trying to explain my reasoning with my wife this AM..... 

[Snowcamo]

I am sure this is the case! I was just trying to explain my reasoning with my wife this AM..... 

Tell her thedifferencein mpg savings is hers to spend.[emoji482]

[MaverickZ71]

18 hours ago, 14wntr said:

Hello everyone,

My new to me GMC Sierra 5.3 4x4 came to me with Toyo Open Country Extreme 2 tires on it that are the following size. 285/55-20 The truck tire spec is for 275/55-20. This truck has no lift and they rub a bit in the turns.  How much could this be affecting my MPG? Would it be worth putting on Highway tires since that is where I spend 99.8 percent of the time? It seems these tires would have more rolling resistance than the correct size/HT instead of larger ATs. I took a 300 mile trip and saw 14.6 one way and 17.4 back. This seems low to me so I wanted to bring this up. My Toyo's are in great shape with very little wear so I could easily sell them. What to do...?

Tire Rack.com says the original equipment tires on your truck were either Goodyear Wranger SR-A's or Continental CrossContact LX20's.  Both of those are highway-type tread.  Switching back to either of those, you would have no more rubbing, your speedometer/odometer would be correct again, and you'd get better on-road ride/handling, better fuel economy, and longer tread life.    

Edited March 20, 2019 by MaverickZ71

[aseibel]

you have several factors working against you:

1) wider tires - worse aerodynamics at speed

2) more aggressive tread - worse aerodynamics at speed

3) heavier tires - more inertia = worse acceleration

 

So you would definitely improve your fuel mileage with the OEM size of a good all season/highway tire.

 

I also run the Cooper Discoverer AT3 4S at OEM size and I don't think it hurt my mileage too much for being a semi-aggressive tread. But you could get a much less aggressive design. See the crap they put on the brand new trucks to compare (mine were Goodyear SRA's). Those are chosen for economy only.

[jaxcam02]

I would buy a set of OEM wheels and tires. I run my 20's and ATs in the city and put my OEM 18's back on when I know I'm going on a big trip. Doesn't take more than an hour to switch them out and reprogram the truck for the different TPMS sensors. Less rotational mass will correlate to more mpgs.

Edited March 20, 2019 by jaxcam02

[TXGREEK]

Hello everyone, My new to me GMC Sierra 5.3 4x4 came to me with Toyo Open Country Extreme 2 tires on it that are the following size. 285/55-20 The truck tire spec is for 275/55-20. This truck has no lift and they rub a bit in the turns.  How much could this be affecting my MPG? Would it be worth putting on Highway tires since that is where I spend 99.8 percent of the time? It seems these tires would have more rolling resistance than the correct size/HT instead of larger ATs. I took a 300 mile trip and saw 14.6 one way and 17.4 back. This seems low to me so I wanted to bring this up. My Toyo's are in great shape with very little wear so I could easily sell them. What to do...?

 

 

You’ve heard it before, didn’t buy a truck to save gas “BUT” would be nice to squeeze out as much mpg’s as possible. Your truck, must be a 16-18 will be happier with stock size wheels. Michelin Defenders will be your best bet and the reason why they’re rubbing is because the tires are to wide. A 275/60/20 will be the biggest size you can put on that stock year range due to the UCA’s being different from the 14-15 1/2 and if it does rub somewhere it’ll be the felt wheel well liner. If you’re looking for best mpg’s? 100% Go with stock size defenders and you’ll see an immediate increase in mpg’s as well as more confidence in driving with better acceleration and braking. Good luck!

 

 

Sent from above

 

[Farmerman1379]

4 hours ago, TXGREEK said:

 

You’ve heard it before, didn’t buy a truck to save gas “BUT” would be nice to squeeze out as much mpg’s as possible. Your truck, must be a 16-18 will be happier with stock size wheels. Michelin Defenders will be your best bet and the reason why they’re rubbing is because the tires are to wide. A 275/60/20 will be the biggest size you can put on that stock year range due to the UCA’s being different from the 14-15 1/2 and if it does rub somewhere it’ll be the felt wheel well liner. If you’re looking for best mpg’s? 100% Go with stock size defenders and you’ll see an immediate increase in mpg’s as well as more confidence in driving with better acceleration and braking. Good luck!

 

 

Sent from above

 

My '18 Silverado Custom 4x4 has 285-45r22 and they dont rub on stock suspension. It's a little over a 32 inch tire. I would've thought 275-60r20 would fit since it's not as wide even though it's a tad taller.

Edited March 20, 2019 by Farmerman1379

[TXGREEK]

My '18 Silverado Custom 4x4 has 285-45r22 and they dont rub on stock suspension. It's a little over a 32 inch tire. I would've thought 275-60r20 would fit since it's not as wide even though it's a tad taller.

Your 285/45/22 tire fits because they’re exactly a 32”. Going taller widens the tire especially going from a 55 to a 60. When stock my 2018 with 275/55/20’s where switched to 275/60/20’s which are 33” rubbed a bit on the inner liner.

[Imcrazy]

I run a 275/65/18 which is a 32" tire... I would suggest the same over all dia. tire for your truck... I would avoid the OEM goodyears they suck... I have been pretty happy with my cooper discoverer atp A/T tires... I see good MPG with them, up to 20mpg hwy with my front air dam removed... I got the same MPG in my 2014 Sierra with highway tires... I much prefer the AT tires in the snow plus they just look cool... Downside for me is the road noise can get a little old but, I just turn up the radio a little bit more... I am on my 2nd set of these tires, they had about 15% tread life left at 45k miles when I replaced them with a new set...