2015 GMC Yukon XL Denali MPG (6.2L, 8-speed)

Campfire Time wrote:
Thanks for posting this. I'm really intrigued by the 6 & 8 speed transmissions. My truck missed the 6 speed by a couple of years.

My dad has the Cadillac Escalade ESV with the 6.2 & 6-speed, and although it's not quite as good as my new truck (newer version of the 6.2 and 2 more gears), it's still night & day better than the old 4-speed in terms of MPG and usable power.

We've done a bunch of side-by-side comparisons between his Caddy and my Suburban before I sold it; we'll do a comparison of the Caddy to my GMC on our next trip to AZ, as neither of us will be towing.

BurbMan wrote:
No doubt, it's a nice looking truck all around, and the fuel mileage with the 8-speed is truly impressive.

My issue is that our TT is 8500 lbs with 1200 on the tongue, so would definitely put us overweight. Have been thinking of the new Ram trucks, but we still use the 3rd row in the burb now and again, so not ready to pull the trigger yet,. I figure I've got a few more years to decide, and it might be 5er time them...

...

I agree with you there. If I had been using my old Suburban to tow our larger trailers, I'd have held off on the new GMC. But I use it mostly for trips to the river, and for towing boats or my flatbed trailer with the Jeep on it - both well within it's ratings.

I don't want to start a debate with the weight police, but I will say this:

While the new GMC isn't rated for as much weight as the old Suburban, I do think it could handle it if properly equipped (tire ratings, etc...).

In terms of stability, braking, on-road handling, etc..., it feels as stout as my 3/4 ton Suburban.

Not that you should, but I bet you could... :B

The mileage didnt change on ours. It was good from the get go and when i got rid of it, it was still getting the same. You can buy them well below msrp, ours was 72 and some change msrp and i paid 63.

Are these hand calculated values or off the dream-o-meter? What grade of fuel you have to run?

N-Trouble wrote:
Are these hand calculated values or off the dream-o-meter? What grade of fuel you have to run?

My first 2 tanks were 87 (before I read that 91 was recommended). Since then I've been running 91, and my butt-dyno says it runs a bit stronger on 91 - but who really knows. I think it's enough of a difference that I'm spending my own $$$ to buy 91 instead of 87. Putting my money where my mouth is there...

As far as hand-calculated vs. the DIC - my initial comments were from the DIC, but I have the gas station receipt and it's not hard to figure out...

I reset the DIC when I filled up on my way out of Arizona, and the DIC was showing 20.1 MPG for 301.0 miles when we got home Monday night.

The next morning on my way to work I got gas and it took 15.3 gallons. A quick Google Map search shows that gas station is 5.2 miles from my home, so 306.2 miles / 15.3 gallons = 20.03 MPG. Given that I was rushing on the way to work and driving pretty fast, I'm not surprise that my MPG dropped from 20.1 to 20.0 MPG.

So in this case the DIC was pretty accurate.

The DIC was always incorrect in my old Suburban, so I'll keep checking this one...

Holy mackrel, that just beats the stuffings out of the mileage I get with the 6.2 F250. :R

Just a note on premium and the DIC on my CTS. My hand calculated mileage is higher than the DIC when using 93 octane instead of 87. This is on the 2.0 Turbo. I believe that my butt-dyno does say that premium is better, and the Shell station sells 93 octane for $.20 more than 87. The mpg is about 1.5 better with 93 octane.