Gas Mileage on 2008 Lux III

[Superjim]

Mine calculates fuel used while idling.

After resetting the AVERAGE MPG indicator... you can drive a few miles on the freeway... pull off at the exit and while idling..waiting for the light to turn..you can watch the mileage drop.

Have also seen it drop considerably while leaving it idling .. with wife in car .. while making a quick stop at the store.

Texas Jim

[BlackDeVille]

I did perform the calculations with a calculator and the trip odometer. The car's MPG calculator is surprisingly accurate; within a tenth either way. I have another long trip coming up this week. I'll try to drive for maximum MPG and we'll see what happens.

[Superjim]

Originally Posted by BlackDeVille

I did perform the calculations with a calculator and the trip odometer. The car's MPG calculator is surprisingly accurate; within a tenth either way. I have another long trip coming up this week. I'll try to drive for maximum MPG and we'll see what happens.

I have quit using the handheld calculator. My cars MPG calculator was, (like yours), usually right on the money.

I find it hard to drive mine for maximum MPG, because it is so much fun to STAND ON IT.

The feel of it pushing you back in the seat, and the sound as it passes 3000 RPM heading to 6500 RPM is hard to resist.

Hmmm... just thinking about what I just wrote... maybe thats why I can never get over 20/21.

Texas Jim

[nosro]

For myself, if I drive 65mph, I can get 25MPG. However, if I average 80-90, I have never been able to do better than 21MPG, even with a very steady foot.

Tires may explain 1-2MPG difference. (I run Michelins rather than the stock Conti's.)

[Superjim]

Originally Posted by nosro

For myself, if I drive 65mph, I can get 25MPG. However, if I average 80-90, I have never been able to do better than 21MPG, even with a very steady foot.

Tires may explain 1-2MPG difference. (I run Michelins rather than the stock Conti's.)

Mine has the stock Bridgestone Turenza tires. 245x50x18
Will probably replace them with Michelin when the time comes. I like Michelin.

Texas Jim

[rjm]

Originally Posted by Superjim

I find it hard to drive mine for maximum MPG, because it is so much fun to STAND ON IT.

The feel of it pushing you back in the seat, and the sound as it passes 3000 RPM heading to 6500 RPM is hard to resist.

Hmmm... just thinking about what I just wrote... maybe thats why I can never get over 20/21.

Texas Jim

And don't you just love the look on neighboring drivers, especially teenagers, because (at least in their minds) a Cadillac could never leave them in the dust. Its an old persons car, and old persons cars don't have any performance capabilities.


Back to the original question: I asked the guys in service, and they said it had more to do with getting the N* to meet the ULEV2 bin??? emission standard.

[Superjim]

Originally Posted by rjm

And don't you just love the look on neighboring drivers, especially teenagers, because (at least in their minds) a Cadillac could never leave them in the dust. Its an old persons car, and old persons cars don't have any performance capabilities.

Yes sir, I sure do.
There are several in my area of town that have a new respect for Cadillacs.

Texas Jim

[z06bigbird]

97 SDV got 30 mpg at 80 mph. DIC showed the 30 mpg. Never checked it around town. CTS get 26 or 27 on highway.

[CalDrvr]

I am new to this group, but have owned a 2007 DTS (Certified Used) since Nov 2007. Shortly after purchase, I switched to Amsoil then changed it again this past April, just before I took a 6 week, 7155 mile trip around the country. I use premium fuel only.

The car has 34,650 miles at the end of this trip, so it is well broken in. I drive the speed limit at all times (get passed a lot) and my highway mpg was consistently 28-29 with town/city mpg about 21.

Overall for the entire trip was 26.7 (total miles vs total gallons). I don't know if this is the fleet average, but I am very happy with these results.

A friend I met on the road drives a 2007 Performance DTS and he was getting 22-23 on the highway which seems in line with others on this forum.

[Superjim]

Just got back from a 1500 miles trip, thru the Ozark Mountains, over the Memorial Day weekend. I took Tuesday off so had four days off.

I made a CONCIOUS EFFORT to TAKE IT EASY.

I am the worlds worst at trying to do TOO MUCH in TOO SHORT of a time. Then I am in a hurry and don't relax like I should. This time I tried not to do THAT.

Overall mileage was 22.9. It would have been a little better but I had to make one emergency run of about 20/25 miles IN A HURRY.

Most of that run was in 2nd and 3rd gear at 3500 to 6500 rpm. That KILLED my mpg average, which up to that time was almost 24 mpg. AT the end of that run, it was down to 19.4.

That is the BEST mileage I have ever got from it. Probably should have reset my AVERAGE indicator, but instead I spent the rest of the trip trying to get it back up to what it had been. Which, of course made me drive easier then normal.

All in all, had a nice relaxing trip with fairly decent mileage.

Texas Jim