Real world MPG - 10 ply tire

[clloyd069]

I recently added a 2.5" RC level to my 2015 Silverado (5.3L 3.42 gears). I also went from the stock Goodyear 265s to a 275/70R18 10 ply tire. Lots of lbs added. I expected my MPG to drop, but the drop that I have experienced is a bit beyond what I expected. Before replacing the tires I took a 320 mile round trip, all freeway and averaged 21 mpg on that trip. Just took the exact same trip, and averaged 17 mpg. Driving conditions were similar....and I maintained a speed of around 76 mph (73 mph per my speedometer, 76 per my phone gps) which is around 1800-1850 rpms. I guess I expected around a 2 mpg drop....4 seems a bit much given this was all freeway driving. What are others getting? It seems like many of you are running a 275/70R18.

 

Thanks.

[dbcooper748]

I recently added a 2.5" RC level to my 2015 Silverado (5.3L 3.42 gears). I also went from the stock Goodyear 265s to a 275/70R18 10 ply tire. Lots of lbs added. I expected my MPG to drop, but the drop that I have experienced is a bit beyond what I expected. Before replacing the tires I took a 320 mile round trip, all freeway and averaged 21 mpg on that trip. Just took the exact same trip, and averaged 17 mpg. Driving conditions were similar....and I maintained a speed of around 76 mph (73 mph per my speedometer, 76 per my phone gps) which is around 1800-1850 rpms. I guess I expected around a 2 mpg drop....4 seems a bit much given this was all freeway driving. What are others getting? It seems like many of you are running a 275/70R18.

 

Thanks.

Im running a very heavy 285/50-22 nitto terra grap setup, and i also took a hit in gas mileage, but i quickly realized that, yes the added weight hurts, but since i went from roughly a 31" total size to a 33.3" total, that the speedometer and odometer is also off as well, causing the mileage computer to register less than i was actually getting so where it said i was getting 18mpg freeway, that after a little math, found that i was actually getting closer to 20

[clloyd069]

Im running a very heavy 285/50-22 nitto terra grap setup, and i also took a hit in gas mileage, but i quickly realized that, yes the added weight hurts, but since i went from roughly a 31" total size to a 33.3" total, that the speedometer and odometer is also off as well, causing the mileage computer to register less than i was actually getting so where it said i was getting 18mpg freeway, that after a little math, found that i was actually getting closer to 20

You're doing better than me then. I did account for the odometer being incorrect. The information center is reporting about 16 mpg on this trip. I'm not relying on it. I've calculated the miles based on my gps, and come out to about 17.3 mpg.

[Huetatos]

Both of you are getting better than me. I've got bridgestone a/ts stock from the factory and I can barely get above 17 on a 400 mile freeway trip.

[Jlm02a3094]

Stock I was getting ~16

Road Armor bumper brought me down to ~14.5-15

BDS 4" lift with 305/65/18 BFG KO2's brought me down to 11

 

Airaid intake and Borla exhaust did nothing to impact the MPG's in either direction

 

For reference, I drive 80% city, 20% highway, and I have a 2015 CCSB Sierra 1500 6.2 with the Max Tow 3.42

 

Josh

[ClemsonFan]

I averaged about 17.5 MPG at ~73-75 MPH on a ~1100 mile trip a few weeks ago. That MPG is not corrected for larger tires. 275/65/20 BFG KO2s.

[TheTunaHunter]

Not sure where the OP is located but I get a dramatic decrease as soon as temps start to drop. Also, I'd have to imagine that those of us in the North East have been filling up with winter blend.

 

My completely unscientific approximations

 

LT/E 275/70/18 DuraTracs , uncorrected speedo/mpg

 

Summer:

Best "last 50miles was 26.8"

Avg Hwy: 21/22

Avg City :14/16

 

Winter:

Best Last 50miles - 22/21

Avg Hwy: 18/20

Avg City: 12 (lots of idling here in NYC)

[redwngr]

It would be interesting to know how much of the drop was tires and how much was the lift/level.

[Bsbalser]

I recently added a 2.5" RC level to my 2015 Silverado (5.3L 3.42 gears). I also went from the stock Goodyear 265s to a 275/70R18 10 ply tire. Lots of lbs added. I expected my MPG to drop, but the drop that I have experienced is a bit beyond what I expected. Before replacing the tires I took a 320 mile round trip, all freeway and averaged 21 mpg on that trip. Just took the exact same trip, and averaged 17 mpg. Driving conditions were similar....and I maintained a speed of around 76 mph (73 mph per my speedometer, 76 per my phone gps) which is around 1800-1850 rpms. I guess I expected around a 2 mpg drop....4 seems a bit much given this was all freeway driving. What are others getting? It seems like many of you are running a 275/70R18.

 

Thanks.

 

You're lucky. I have the same set up and in getting 11.5-13 mpg

[foo.c]

I'm probably in the minority, but I will never put E rated tires on a half ton again. Terrible ride, robs mpg, and robs power.

[Rawyzf]

I'm probably in the minority, but I will never put E rated tires on a half ton again. Terrible ride, robs mpg, and robs power.

 

E rides the same (or very similar) when you put the correct PSI in them for driving without a load (40ish PSI). I'm talking A/T P vs A/T E, also for comparison sake.

 

I went from 275/60/20 A/T P tires to 285/70/17 A/T E tires, I just took the average on the last 5 tanks to compare the difference (hand calculated).

P275/60/20 A/T Cooper ATP 16.94

285/70/17E A/T Cooper ATP 16.61

 

Where I think most people really take the hit is going from the GY SRA tire to a real A/T tire.

[crafferty]

I recently added a 2.5" RC level to my 2015 Silverado (5.3L 3.42 gears). I also went from the stock Goodyear 265s to a 275/70R18 10 ply tire. Lots of lbs added. I expected my MPG to drop, but the drop that I have experienced is a bit beyond what I expected. Before replacing the tires I took a 320 mile round trip, all freeway and averaged 21 mpg on that trip. Just took the exact same trip, and averaged 17 mpg. Driving conditions were similar....and I maintained a speed of around 76 mph (73 mph per my speedometer, 76 per my phone gps) which is around 1800-1850 rpms. I guess I expected around a 2 mpg drop....4 seems a bit much given this was all freeway driving. What are others getting? It seems like many of you are running a 275/70R18.

 

Thanks.

Looks normal to me. Larger tires and 10ply will have a great affect on your MPG's. For one they are larger in diameter so it takes more power to get the truck rolling and to keep it rolling. Then you factor in the extra weight and additional rotational force and all that jazz it adds up. You have to pay to play.

 

 

E rides the same (or very similar) when you put the correct PSI in them for driving without a load (40ish PSI). I'm talking A/T P vs A/T E, also for comparison sake.

 

I went from 275/60/20 A/T P tires to 285/70/17 A/T E tires, I just took the average on the last 5 tanks to compare the difference (hand calculated).

P275/60/20 A/T Cooper ATP 16.94

285/70/17E A/T Cooper ATP 16.61

 

Where I think most people really take the hit is going from the GY SRA tire to a real A/T tire.

I would have to agree with what you saying about E rated tires. I run my Toyo R/T's at 42 PSI and they ride virtually the same as stock or at least my butt can not feel a difference. Now I do have aftermarket coilovers which helps too. But even my 2012 Denali with Toyo AT's rode very nice as well. What's interesting about your tires is that you actually went down in size but increased weight (5lbs) and your mpg still took a hit. It just goes to show that the extra weight really does affect MPG's.

[SouthpawHD]

Not sure where the OP is located but I get a dramatic decrease as soon as temps start to drop. Also, I'd have to imagine that those of us in the North East have been filling up with winter blend.

 

....

 

^^^ This. Winter fuel blend sucks and decreases fuel mileage.

 

OP, give it a few more miles and trips and see where you end up.

[crushNchowda]

It is the weight of the tires, I planned on going to 275/65/20 BFG KO2's in the spring - on stock rims. The BFG's (and it seems the Nittos and Toyos are very similar) weigh about 57 lbs, the SRA's in 275/60/20 weigh about 39 lbs - that is a SIGNIFICANT difference.

One thing I have realized though swapping over to my winter tire setup - the stock rims are quite heavy. I need to weigh it to get official, but I'd say the difference between my stock AT 20" wheels w/ 275/55/20 Wrangler SRA's vs. my granite alloy 20" aftermarket wheels w/ Michelin snow tires in the same 275/55/20 size has got to be 10 lbs at least - I can immediately tell the difference hauling the setup up and down my cellar stairs.

One cure or at least a help to the MPG hit if you're going to run heavier/larger AT tires is also swapping the stock rims out for something lighter....so I may end up using my stock rims as winter wheels (don't really want to!) and the granite alloy black wheels for summer/fall etc.

[crushNchowda]

It is the weight of the tires, I planned on going to 275/65/20 BFG KO2's in the spring - on stock rims. The BFG's (and it seems the Nittos and Toyos are very similar) weigh about 57 lbs, the SRA's in 275/60/20 weigh about 39 lbs - that is a SIGNIFICANT difference.

One thing I have realized though swapping over to my winter tire setup - the stock rims are quite heavy. I need to weigh it to get official, but I'd say the difference between my stock AT 20" wheels w/ 275/55/20 Wrangler SRA's vs. my granite alloy 20" aftermarket wheels w/ Michelin snow tires in the same 275/55/20 size has got to be 10 lbs at least - I can immediately tell the difference hauling the setup up and down my cellar stairs.

One cure or at least a help to the MPG hit if you're going to run heavier/larger AT tires is also swapping the stock rims out for something lighter....so I may end up using my stock rims as winter wheels (don't really want to!) and the granite alloy black wheels for summer/fall etc.