For full highway driving I got 30 at 70mph and 28.5 at 75.

Around town is 22. Combined is somewhere in between. Last few days was 26.7.

 

Bringing this old thread back.

Our HSE Lux Si6 gets around 19-20 MPG on the Highway, but in normal commute and around town it seems to average 15 MPG. This is calculated by hand using gas pump and odo.
The MPG indicator seem to say around 17MPG for around town and work commute (which includes some highway).

Anybody else notice that the MPG indicator seem to be optimistic by 1-2 MPG sometimes. I have not ever seen it get more by hand calculation than the MPG indicator. Not a fill more or less pending gas pump.

This is using premium 91 at Chevron or Shell. It is CA gas in the winter though, where I know CA gas is not as good for MPG than some other states due to all the crap they put in here.

The Si6 only has about 3500 miles on it now, so will see if things get a bit better after 5k or 10k miles.

 

My 2017 HSE consistently gets about 22 mpg with mixed city/highway driving using Costco premium fuel. This includes some mountain driving.
I don't drive it hard. The onboard computer is usually 1 to 2 mpg higher. I can get 25 mpg on an interstate highway trip of 150 miles or so.
And I have no throttle lag.

 

Ours is a 2019, hope it gets a bit better with time (though not bad for a vehicle this size). Wish we didn't have the lag issue.

Also probably need to add my wife drives it mostly and she is an enthusiastic driver I am also not the slowest driver, but try not to be too hard on it.

 

 

I have 5,400 miles on mine...I don't drive too slow or too fast. I use Premium non ethanol fuel. Avg. 17.9 mpg according to the computer in the car. I am actually disappointed. My prior 2015 Yukon Denali with a 6.2 liter V-8 (over 400 hp). averaged almost 20!

 

I have the Td6 in my 2018 DV and for the first 10,000 miles with the stock 235-65R19 Pirellis I averaged 26.1 MPG with an average speed of 35 MPH. At about 10,000 miles I switched to Cooper Adventurer ATs in 275-55R20 and currently average 25.1 MPG, but with the increased roll out of the larger tire it is actually closed to 25.7 MPG with an average speed around 35MPH. I'm currently just over 16,000 miles. I find that elevation gain or loss makes a big difference in my fuel economy. In my one way commute to work I have a roughly 1,000 foot elevation drop and regularly get 30 MPG, on the way home, I'm hauling it all back up the hill and the mileage suffers accordingly. I have had mileage as high as 40MPG on a one way trip (50+ miles) primarily downhill mostly highway (and likely a tailwind). I bought the TD6 knowing my longer commute (30 miles each way), the relatively low entry cost for the diesel (as compared to other offerings), the lack of engine noise, the torque, and the much better fuel economy/costs (especially when the Si6 should be running on Premium). I'd highly recommend the Td6 unless you do a lot of stop and go travel and have short commutes. It has been the experience of some of my friends that this type of driving does not work well with diesels requiring DEF (regardless of brand).

 

Wow that's impressive. My wife's TD6 only has about 3000 miles on it...I'll check her mileage to date for comparison.

 

Did you need the Johnson lift to install those Dura Tracs?