Gas mileage if changing to 35s ?

[ugaDAWGS09]

Anyone here with a 19 GMC and 35s what kind of mpg are you getting? I have a 19 Sierra with the 5.3L and 3.23 gears.  Will these gears even run the 35s without feeling sluggish or should I stick with 33s? I've been getting about 21 mpg on the highway so would hate to get less than 16 on the highway. 

[smrr1]

I’d personally stick with a 33 or maybe a 34 and look at multiple tires. Check their weight. They can vary a lot. The weight will make a huge difference in fuel and brakes. 

 

However if you must go 35 i would guess you would see a 12-17% impact with the same conditions and driving style as now. 

[ugaDAWGS09]

Since the stock tires already have a diameter of 33 inches, should I be able to fit a more aggressive 33 inch tire with just a level kit?  I was looking at a set of 33x12.5x20s.  

[f8l vnm]

1 hour ago, ugaDAWGS09 said:

Since the stock tires already have a diameter of 33 inches, should I be able to fit a more aggressive 33 inch tire with just a level kit?  I was looking at a set of 33x12.5x20s.  

Stock tires are like 32 inches 

[Donstar]

If you're buying new tires for looks, then I suggest taking your time, look around, and continue the discussion with other '19 owners. If you need a more aggressive tire now to take you to remote locations then consider remaining with close to stock size.  (I sometimes go +1 on the width or aspect)  Your best highway and city performance will be achieved with remaining stock. Looks are important but spending a large amount of money to replace new tires for a negative impact needs serious consideration, imo. When I go slightly larger, it is strictly for my personal mini-macho  boost.  I know very, very few people who would notice or value larger tires on my pickup :-)

[aseibel]

1 hour ago, ugaDAWGS09 said:

Since the stock tires already have a diameter of 33 inches, should I be able to fit a more aggressive 33 inch tire with just a level kit?  I was looking at a set of 33x12.5x20s.  

You have a two-fold effect on your fuel economy to consider: Taller/wider/heavier tires with large lugs will affect your mpgs due to their own physics. But if you level the front, you are also adding wind drag/resistance on the highway due to changing the way the wind flows around and under the truck. You can decide how much you value the appearance of the truck over fuel economy. Making changes you are suggesting will certainly knock off a couple MPG's, but I think you'd still be above 16 highway like you suggest.

 

Your gearing is another problem. You will notice the truck laboring a bit more to accelerate. Not so bad that you can't drive normally, but it will be more of a dog. If you want it to feel like stock, you need to correct the gear ratio to compensate for the larger tires. There goes another $2,000.

[FiatDale]

Easiest answer - you’ll drop about 2mpg depending on the tire. Your gears are fine. I ran 37s on my 2010 with 3.08 rear for 3 years no issues. It’s not a rocket ship, it’s a pickup. Still could get up and go when it needed.

[Wiggums]

Adding a lousy couple inches to my Isuzu Trooper saw a huge drop, from a so-so 16 mpg to 12-13 mpg. You'll be messing it up with bigger tires, not worth it

[smrr1]

The only person who can answer if its “worth it” is the owner.

 

If you need them to get to places go get them but if just for looks it is just for you. The comment made earlier that most people will not notice or care is very true. I’m struggling with the idea of changing tires on my AT4. No one cares but me and i don't really need anything more aggressive. $800-$1000+ for tires that will cost more money in gas is a hard pill to swallow. 

 

 

[Black02Silverado]

Mostly any time you change from the factory tires your mpg will take a hit. How much just depends on the tires. Each weigh differently and so that will effect the mpg as will the diameter.

[Kylebr1]

I am currently getting 15.8L per 100 with 35s . Very minimal change from factory size . Tires are toyo open country at . 

[amxguy1970]

4 minutes ago, Kylebr1 said:

I am currently getting 15.8L per 100 with 35s . Very minimal change from factory size . Tires are toyo open country at . 

So about 14.8 mpg? Doesn't sound like a minimal swing from stock...

 

Tyler

[Kylebr1]

My truck is a 2016 5.3 6 speed . With AFM off . Truck has never gotten better than 14.8 liters per 100 its entire life . 

[Starbuck41]

I put 35’s on my stock trailboss..no diff in mpg.  Maxxis at’s.  You’ll like em, great in snow and hwy

Edited December 3, 2021 by Starbuck41

[Gangly]

I went from factory Bridgestone 33’s to DuraTrac 33’s when I did a 2” level and dropped a combined 2-3 mpg from the tire/level.  As mentioned above, tire weight will be the most critical component when changing tires.