: 2008 STS 3.6 RWD Fuel Economy



Rushnack
10-16-12, 11:29 PM
I have a 2008 STS 3.6 RWD with 47k miles.. I took my 1st real long drive 120 miles... I was thinking I would get real close to 26 MPG on the freeway but did not... I had the cruise set at 61MPH and wen i got to my destination and then returned the DIC read out to 22 MPG avg... That seemed a bit low.. What is any one else's experience ?

dannyquest
10-16-12, 11:53 PM
At 60- 65 mph. 06 STS V6 I get about 25 mpg. This is on flat free ways in Ohio. 20-22 mpg. city. Danny

carter's_sts
10-17-12, 01:38 AM
Rushnack, did you reset it before the trip? Otherwise 120 miles wouldn't be enough to move your rolling average up. In my 06 with AWD I got around 28 on a 600 mile trip once. And my 3.6 should get worse mileage than yours.

truckinman
10-17-12, 03:03 AM
In my 05 V6 I can get 28 believe it or not, at 60 if it ONLY factors the mpg after youve set the cruise so you don't factor in the acceleration. But just the cruising.

Hoosier24
10-17-12, 11:15 AM
I like to use the average gas mileage feature and reset it with every tank of gas. At best I average 18.8 to 20.1 mpg per tank. On hwy trips the best I've ever averaged is 23.9 w cruise at 75-78 mph. I have a 2009 v6 1sg.

truckinman
10-17-12, 11:18 AM
I like to use the average gas mileage feature and reset it with every tank of gas. At best I average 18.8 to 20.1 mpg per tank. On hwy trips the best I've ever averaged is 23.9 w cruise at 75-78 mph. I have a 2009 v6 1sg.

When Im on a trip, if I reset mine from the time I fill up, I'll average about 24-25 over all cruising around 70.

C&C
10-17-12, 12:29 PM
My '06 got between 24 and 25 mpg (hwy mileage), it had a 3.42 rear axle ratio; my '11 gets just a tick more or less 30 mpg (hwy) with an axle ratio at 3.23 with speeds between 65 and 70 mph (both cars).

Ludacrisvp
10-17-12, 01:12 PM
How's your tire pressure and alignment?

Loren
10-17-12, 02:54 PM
Two years ago I took a trip from here in Utah to West Virginia, just over 5,000 miles total, round trip. After getting out of the Rockies in Colorado onto the relatively flat land I averaged right at 31 mpg measured at the pump, not the on board computer which showed 28. I'm very satisfied with the mileage I'm getting.

EChas3
10-17-12, 08:18 PM
The DIC isn't always accurate.

Rushnack
10-18-12, 11:09 PM
All very good replies...Thanks.... Tire and alignment are good.. Sounds like when I go on a real road trip I should see much better results. Either way Im very pleased with this car.. I used to drive a 2001 Ford Focus ZX3.. Im 6'3 and that was a bit tight.. Now Im cruising is luxury !!!

buzz
10-24-12, 03:22 PM
I never checked the accuracy of the MPG on the DIC for my 2008 STS; however, over the past 6 months, I am averaging 21.8 with AWD. My wife's 2008 SRX AWD (basically the same engine, 5 speed trans) averages 19.8 MPG. My last Cadillac, a 2003 Seville STS averaged 18.9. So, with almost 3 MPG better economy, I am not disappointed.

jokaf0life
10-24-12, 10:45 PM
I took a road trip from Nashville to St. Louis in July 2012 in a 2008 sts 3.6 and I averaged about 28 round trip

KRSTS
10-25-12, 10:19 AM
Somehow I doubt that is accurate

Ludacrisvp
10-25-12, 01:33 PM
if its RWD and has the 2.73 drive ratio I could believe it.

EChas3
10-25-12, 08:39 PM
28 MPG is easy in a RWD V6. My wife's V8 could get 25 at 80.