[ECha3]

I have the window sticker. It is a 2006 2wd, not AWD, 1SG, and the EPA #s are 17/26. There is no gas guzzler tax on the sticker. The car is under warranty. If 23 mpg at 70 is normal, I can handle that. If it is not, I will take it to the dealer to fix it. Just looking for a little help from my new friends. BTW, here in the Atlanta metro area we have 'boutique' fuel. (Thank you EPA!) Is it possible the energy density in the summer blend is less than optimum? Thx!

No offense intended. Sorry.

What RPM's do you have at 70 MPH?

 

[MacMuse]

Here are the numbers for 2006 STS's city/combined/hwy

v6 rwd 16/19/25
v8 rwd 15/18/24
v8 awd 14/17/21
v8 V 12/14/19
...

Cool, anyone trading in their V8 under the Cash for Clunkers program? :hide:



just kidding.

 

[D&Ds_STS]

The numbers I quoted are per the "revised" EPA ratings and they will be different than some window stickers. Since the procedures changed during the years, there was no good way to compare cars, so they have revised all numbers per the latest procedures. That doesn't effect what you are saying about your 2006, just what the EPA currently lists. For anyone interested, got to: http://www.fueleconomy.gov/ and click "compare side by side". It's a nice tool to look at all of the permutations of models.

Thank you! I did not know the gov't had re-rated older vehicles. I wish I could re-negotiate my performance objectives.

 

[D&Ds_STS]

What RPM's do you have at 70 MPH?

2400 at 70 mph. MacMuse posted "My '06 STS mileage falls off dramatically above 2000 RPM. But below 2K it does very nice - except I get passed by everyone else on the highway." I will try a steady 2000 rpm when I get a stretch of road where my butt won't get run over. Hard to find around Atlanta. Maybe a Cadillac tech type can explain if there is something going on with VVT, ignition timing, or mixture that kicks in above 2000 rpm at light load that affects fuel economy?

I appreciate all the info. I feel better now that it appears my car is thirsty, but not sick.

 

[KARL DAHLEN]

Cool, anyone trading in their V8 under the Cash for Clunkers program? :hide:



just kidding.

I traded my old 92 STS with a blown HG for a new car for my son. It was rated at 17 combined. I knew I was keeping it around for a reason.

 

[ECha3]

This morning I looked closely. 55MPH is 1,800 RPM in my 2006 AWD V8. It would get better than 21 MPG at that speed.

Over 2,000 RPM the N* starts to breathe. I think that's where all pretense of economy comes to an end and the torque comes on. After all, torque is what accelerates cars. Horsepower may determine top speed but the game is more about quickness than speed.

Those old Duesenburg's produced 265 normally aspirated HP similar to our cars but the torque exceeding 300 ft-lb's moved those 3-ton cars nicely for their era. 0-60 in 9 seconds and 100 under 20 seconds.

 

[KARL DAHLEN]

Just checked, my 08 V6 turns 2000 RPM at 70 MPH and mileage is between 28 and 29 at that speed. Not too shabby.

 

[D&Ds_STS]

Just checked, my 08 V6 turns 2000 RPM at 70 MPH and mileage is between 28 and 29 at that speed. Not too shabby.

That's very good! We got about the same with our '04 CTS V6, and I'm guessing the STS is a bit heavier.

 

[next2pool]

Just checked, my 08 V6 turns 2000 RPM at 70 MPH and mileage is between 28 and 29 at that speed. Not too shabby.

That's the direct injection version--over 300 hp with great mileage. very sweet!