PawPaw

Not the first truck I've had that's leveled with larger and heavier tires so I knew what would happen. I needed to use heavy LT tires to avoid getting flat's on job sites and for better traction in mild offroad condition's. I was driving at least 100 miles a day and needed tires that would last at least 2 to 3 yrs. Now that I'm retired and not running in these conditions anymore I may go back down to P rated tires for weight savings and a little better mileage if I can ever wear out these Terra's. I may try a P275x60x20 in a Michelin or BFG next. Must be getting old!! Going to put some miles on them now!!

bamabat

Paw Paw, I just put the same setup on my truck as you except in the P-rated tire. So far I have noticed ~.5 MPG difference. Didn't think that was too bad. Ordered SCT 3015 that is supposed to be in today. Anyone use this with per-installed tunes?

L2C

I have the eb engine with 3.73. I don't know how u lost 5 mpg. That's a lot. I used to have an excursion with a 10" lift and 40" toyo m/t tires and didn't lose that much but maybe cause it was diesel

justjimmy

Yea, it does seem like a lot.

My Bilsteins are set to 1.95" so they aren't all the way up.

Mike at 5 Star sent me a tune that corrected for tire size and its dead on with my GPS.

The only thing I can guess is the tires are 10 ply and very heavy.

The best I can get on the highway is 15-15.5 MPG. Prior to the changes, I consistently got 20-21 MPG.

Haven't changed driving habits or routes.

Not happy but, I did it, so I'll live with it.

Blue_76

I dont know how you guys get such good mileage with these things. My 2011 Screw with the 5.0 has never gotten anywhere close to 20MPG no matter how hard I try to baby it. Sure I can reset it on the HWY once I am up to speed and it will hold above 20 until the first hill. But buy the time I get where I am going it is alway under 18 on the hwy... that isnt bad but it isnt 20 or 21. In mixed driving I am alawys 16.4 to 16.6 every week.

Stock tires... no level...

Greg

Murderisthegame

Custom performance tuning and smaller things like CAI and exhaust to help her breathe... that's my secret.

klumb15

Where did you find a p-rated 305/55/20?

bamabat

My local tire dealer found it. It is actually an XL load rated tire. Little cheaper and no where near as heavy as the 10 ply. Got them for $1375 installed. Here is link on Nitto site.

http://www.nittotire.com/Tire/terragrappler#size

justjimmy

I also have Dual Cat Back exhaust and a custom tune - no CAI but I do have a K&N air filter.

Before that, I would get 18-19 mpg. Those items did help boost the mpgs up but the tires killed it again.

Oh yea... REAL IMPORTANT information - I live in South Florida where there are virtually NO HILLS and I do have a 2WD truck with 3.55s. I'm SURE this helps!

TylerB

This is what I plan to do!