Cadillac Seville / Cadillac Eldorado Forum Discussion, Best MPG you've observed in Past Cadillac Vehicle Discussion; Hi everybody. We have a 2004 Seville and we have taken it on trips but the best MPG we got ...
Hi everybody. We have a 2004 Seville and we have taken it on trips but the best MPG we got was 23 and change. We drive 70-80 on freeways and are using regular, not premium.
My previous car was a RWD Pontiac Formula with a supercharged and modified LT1 with 500 HP and I could get 24.8 doing 120 mph. So, if the common knowledge is FWD is more efficient and HP used more fuel, why doesn't this Cadillac get better mileage?
I drove my Pontiac from Las Vegas to LA one Christmas morning at dawn which was a Sunday also and no traffic. 2000 RPM was 80 and 3000 rpm 120 I nade the trip in record time and filled each end to ck mileage. Even at 80 I got 25 MPG.
Seems low. I average little over 23 on my daily commute a 14 mile drive of mostly 45mph and a portion of downtown city blocks. I believe my last highway trip was 29 or 30 mpg at 70 to 75 mph with 87 octane.
Automobile(s): 2001 Seville STS, 1990 Seville (RIP), 1972 Sedan Deville
East Boston MA.
25 MPG @ 80 MPH, and only .2 MPG at 120 MPH (double the speed limit on Christmas morning, nice...), with a supercharged V8? .....No, not even if your Pontiac was a super light, hyper aerodynamic prototype.
Long trip, level ground, consistent legal speeds, ~26-28MPG in an SLS.
Automobile(s): 2002.5 F55 STS, 2014 Explorer XLT 4WD
MD Eastern Shore
Re: Best MPG you've observed
2002 STS, 7 round trips to Florida and back - Shell 87 (higher octanes make absolutely no difference - tried everything except snake oils), 24.8 mpg at I-95 speeds - which vary between 60 and 80 depending on state/traffic, plus the off-ramp to motels and food/fillups figured into the average - using a hand calculator and the onboard calculator.
A SLS or ESC in good condition will easily log 26+ mpg under those conditions ^^^.
As always, mpg depends on weather, load, mechanical condition, tires, and black magic. To help long run highway mpg a tad, carry 32 - 34 psi (cold) in the tires.
BEST observed ??? 25.3 mpg, 56 miles at a purposeful 55 mph.
You didn't mention that your Seville is STS or SLS. But because it is '04, and assuming that you live in the US, I am going to say it is a SLS. 23MPG on highway isn't very out of line. Actually the estimated highway gas mileage for SLS is around 26-28, I think!
Based on my personal experience with my STS, which has a worse gas mileage compared to your SLS, if i keep a setady speed of 65-70 MPH, I can easilly get 24MPG. But in a packed highway, where I need to brake, accelerate, and pass other cars, 20 MPG is what I get. City is a totally different story! Right now my average MPG is around 10! My daily commute is one mile per way, and there are more than 10 stop signs and traffic lights combined between my house and my work!
Automobile(s): '02 ETC 32,000 miles 2002 F55 STS 69,000 miles
Black Hills of SD
Re: Best MPG you've observed
Just the other day I drove 300 miles on just under a half tank in my ETC. Really, I swear.
That's gotta be 30 MPG or better.
The tank was topped off and I think I may of had a tailwind for a good part of the trip.
What's the capacity of the stock tank on a '97 ETC?
18 gallons, 20? ..........I've never really paid attention and I rarely let it get close to empty before fill-up.
That was averaging probably 75 mph, on mostly flat road, with bran-new tires at 35 psi.
I have done many trips from Seattle to Bremerton which is about 80 miles and I averaged over 28 MPG sometimes getting around 31-32 with it on cruise control at 60-65. But when I take it off cruise control I average about 27 until I get in the left lane...