2000 ETC. First road trip since bought. 38k second owner. At 2000 RPM (70 MPH) 23.5 MPG. At 2500 RPM (79 MPH) 28.5 MPG. Never have I owned a car that got better MPG at higher RPMs. The sweet spot, as I see it, is at 2500 RPM. Has this been addressed somewhere else on here? If so would someone direct me to the postings.

Can't help with the posting but FWIW, I just purchased my '02 SLS in Canton Ohio and drove it home (450 miles). I averaged over 31 mpg til I hit nw Indiana and the southern Chicago burbs.

Just after buying my 96 SLS three years ago, work required me to follow a semi to a job site 300 miles away. I followed a half mile behind, on cruise at 66 MPH for what seemed forever. I started with a full tank and all readouts cleared and reset. The MPG average was amazing...slowly rising till it settled between 32 and 33 MPG. The subsequent fillup verified this to be actually above 31 MPG. I don't have the patience to try to duplicate that, but I can readily get 26 - 28 MPG on pure freeway use, while maintaining 70 - 75 mph.
And all this time to have all that power there to use if you "need" it. Is this great or what? :thumbsup:

Man, the tranny in the STS really needs another gear to get the good mileage you're seeing in the SLS.

I got about 21-22mpg in my '92 deVille at 75mph for 163 miles this weekend. I'm satisfied.

For short term use I've got 205/40/17 tires on my ETC. I see the best mileage around 70, which is maybe 2450-2500.

Somehow I'm managing 18.9 this tank, 10 miles worth of highway, 8 1/4 mile passes at the track this morning/afternoon, the other 50 miles city. I'm impressed.

I get approx 18 -20 highway this car was made for the highway It hates South Fl traffic 15-17 city drops signif

I get approx 18 -20 highway best ever was 23 going to So Carolina this car was made for the highway It hates South Fl traffic 15-17 city drops signif:(

I borrow my mom's Eldorado to pick up my kids in NY once a month, 700 mile round-trip, I usually get 25-26 running 75-80 mph. Dad will get around 28 heading to Florida for the winter in his car, he keeps it around 70 mph. For a big car, the N* gets really good mileage.

I agree... I dont understand why the northstart gets such good gas mileage compared to other cars that weigh similar..... Must be FWD and less drivetrain losses or something.....

also... are you guys figuring out your actual MPG or going by what the computer says?

I believe the computer more than I do a gas pump. The computer has no reason to rip me off... :p Not to mention since it's FI, it knows exactly how long the injector pulsewidths are and how much fuel is flowing through them.

21 more posts till the big 5K dave!
its only 4:07 AM ET, plenty of time :)

Still I think id like to check both... its not hard...

Also as the injectors wear they cna leak just a tiny bit more fuel.. I dont know, whatever the case is you guys get better mileage than I do.....

I believe the computer more than I do a gas pump. The computer has no reason to rip me off... :p Not to mention since it's FI, it knows exactly how long the injector pulsewidths are and how much fuel is flowing through them.

And doesn't know how clogged the injectors are, or what the exact fuel pressure is, either...

To my understanding...
It knows the fuel pressure within a couple percent as long as the FPR is good. It also monitors the O2 sensors and will adjust pulsewidths as necissary to match the air/fuel map, so it should still know how much fuel is flowing.