For Those with BFG KO2s...

[swathdiver]

Howdy,

Just bought a 2009 Yukon XL 4WD with the LC9 and 3.42 gears. It came shod with BFG Rugged Trail 275-70-17 - Load Range E. On a 700 mile trip averaging 78-80 mph the truck got 17.5mpg. Around town 12 or 14.5 if I baby it.

The tires have good life but one is pretty dry rotted on its sidewall. Looking at KO2s in Load Range C (6-Ply) or E (10 Ply).

What sizes are y'all runnin' and what kind of mileage are you getting?

These trucks were advertised as getting 15 city and 21 highway. I'd like to get close to that if possible with LT tires, especially on the highway.

What is the sweet spot for good highway mpg for the 5.3?

Thanks.

 

[DrunkElvis]

I'm not sure what these trucks were advertised as getting mileage wise but it had to have been better than 21hwy. I was getting 22-24 with my stock 255/60/20's and I averaged 20.5 tonight after a 180 mile trip on my new 275/60/20 KO2's. I've been averaging 19.5-21.5 on the highway with these new tires depending on how aggressive I am.

 

[swathdiver]

My window sticker doesn't have any mileage ratings but the reviews, some GM ads and fueleconomy.gov all use the 15/21 figures for the 2009-2014 with the 5.3.

With stock 20s, I think you'd have the highway gear, the 3.08, and thus would get better mileage than rigs set up for towing.

How fast are you driving to average 20.5? I got 17-18 doing 78-80 on a 700 mile trip. If slowed to 72mph or so, it got around 20-21. If those construction site radar gun signs are accurate, my speedo is 2mph fast.

 

[swathdiver]

Bought a set of 6-Ply BFG All-Terrain KO2s and had them installed today. Big difference over the 10-Ply BFG Rugged Trails. Mileage instantly jumped from 13s to over 15, even getting on it a bit. Way less rolling resistance, the truck is certainly faster now and coasts longer too.

They started out a bit noisier and after about sixty miles they've quieted way down. The KO2s also offer a smoother ride and some of the neighborhood bumps were barely noticeable now.

As an aside, I took the truck the CAT Scales and she weighs 5900 pounds with nearly a full tank of fuel. Weight distribution is 52% on the steer axle, 48% on the drive axle. Fun stuff.

Correction to first post: The BFG Rugged Trail tires are the stock size, 265-70-17 as are the new KO2s.