: Where did the MPG go?



mtflight
12-16-08, 07:00 PM
It's hard to ignore that the current generation (06-'10) DTS has an EPA rating of 15 CITY/ 23 HWY (LD8)
15 CITY/ 23 HWY (L37)

The 2000-2005 Deville was rated at

2002-2005 18 CITY / 27 HWY (LD8 and L37)
2001 16/27


Where did the fuel economy go?

97EldoCoupe
12-16-08, 10:40 PM
That's a good question. With technology advancing, you'd think the internal combustion engine would become more thermal efficient.

eyekandyboats.inc
12-16-08, 10:49 PM
my dts on hi way will run 25 MPG avg which is awesome. and i usually drive at 120-140 ish and i LOVE the power.
in town it sucks i see any where from 14-17 mpg... Mind you i am one of those people who don't drive like a grandpa.
However!!! my 1994 ETC had the best fuel economy i pulled 28 mpg on hi way ( same drive) and 18-21 in town ) same town.
it was great! man i want to get that car fixed up so badly some day.. it just beautiful!

97EldoCoupe
12-17-08, 06:37 AM
My 97 pulled 29.1 MPG doing 130 km/h home from Manitoba through the USA - N. Dakota, Minnesota, Wisconsin, Illinois, Indiana, and Michigan. It's an absolutely awesome cruising car.

From some of my other posts you'll probably notice my '97 doesn't have the LD8 or the L37- it has the L47 Aurora engine with 3.11:1 gears. Take-off isn't too bad but not what my STS does. However, did a race beside my '98 (friend was driving the Eldo) and above 100km/h(60MPH), the Eldo was pulling right beside my STS with the L37/3.71:1 - we stayed even. I could not believe it. The 4.0 with 3:11s can keep up at speed. Gas mileage is awesome with the 4.0.

97EldoCoupe
12-17-08, 06:38 AM
Hey Eyekandy, why don't you still drive your '94?

eyekandyboats.inc
12-17-08, 08:42 AM
Its a long story.
one owner... me since 1994. driven from Missisauga to Orillia every day 5 days a week since.... 1994-2001 summer only. and it has 394K on it... all hi way as you can assume. then i got the ETC(01) and my 94 became a winter car the car is still in GREAT shape and i wanted to keep it. I had it for sale for a while But realized the money i was going to get for it. inst even worth it, its just such a nice looking car , i like the bumper covers and rocker panels Much better then the new eldo's because they are short and more muscular.
SO it is in my garage where it will stay until the time when i will be wanting to get some things fixed, Such as a the white smoke coming up from the back of the engine near the coil pack and a new driver seat.
that about why. I would love just to drop a new engine it and find a seat for it. I like it and don't really want to get rid of it

you can Just see the front end right here
http://i152.photobucket.com/albums/s174/eyekandy19/IMG_3262.jpg
http://i152.photobucket.com/albums/s174/eyekandy19/Picture920.jpg


Hey Eyekandy, why don't you still drive your '94?

eyekandyboats.inc
12-17-08, 08:46 AM
Thats nuts! but awesome!does it take much work to get a 4.0 to fit?
can 4.0 just "bolt" right into a Cadillac, how does the PCM handle it?
There are two STS's up for sale by me ( beside one another) ones a pre 1995 and the other is a 98+ blue and red both are in good condition body wize but they are sitting on the hull with for sale signs... poor cars


My 97 pulled 29.1 MPG doing 130 km/h home from Manitoba through the USA - N. Dakota, Minnesota, Wisconsin, Illinois, Indiana, and Michigan. It's an absolutely awesome cruising car.

From some of my other posts you'll probably notice my '97 doesn't have the LD8 or the L37- it has the L47 Aurora engine with 3.11:1 gears. Take-off isn't too bad but not what my STS does. However, did a race beside my '98 (friend was driving the Eldo) and above 100km/h(60MPH), the Eldo was pulling right beside my STS with the L37/3.71:1 - we stayed even. I could not believe it. The 4.0 with 3:11s can keep up at speed. Gas mileage is awesome with the 4.0.

97EldoCoupe
12-17-08, 10:41 AM
Other than some accessory brackets, and the oil pressure sensor, the 4.0 is a direct bolt in. The accessory brackets just have to be used from the 4.6 and the A/C compressor as well. The intake with fuel rail is used from the 4.6. The PCM runs it with no problems, even passed the emissions test with the 4.0.

I bought it with a 4.0, likely the original 4.6 gave up so thats probably the onle N* they could find at the time. I had a low oil pressure condition with the engine I bought it with, so the only N* I could find at the time, was again a 4.0- did the HGs on it and installed it. One great running car. Just wish it had a bit more low-end torque. I have all kinds of engines now, so when I get a chance, a LD8 or L37 is going back in the car.

Steady cruising with the 4.0 at about 85 km/h (about 52 MPH) I averaged 6.8 L/100 kms or about 34.5 MPG (us gallon) over a 2 hour drive down highway 3 from Aylmer to Leamington, ON.

97EldoCoupe
12-17-08, 10:42 AM
Those are two beautiful Eldos there, Eyekandy! the DTS isn't bad looking either!:thumbsup:

mtflight
12-17-08, 01:22 PM
Yeah very beautiful Eldos. I miss mine. I like the firmer steering on my DHS--and the car overall feels more like a spaceship than the Eldo did.

Edit: I did find out the EPA changed their MPG estimates, to be more accurate (faster highway speeds, more stop and go, etc). But that still does not explain the MPG loss of the latest FWD Northstar vs the one right before it.

eyekandyboats.inc
12-17-08, 05:20 PM
Thats awesome! i wish i could pull 34+ mpg at that speed. But i dont concern my self with good fuel economy. it doesn't bother me to much.




Well today i drove economical to work and tried to squeeze all the efficiency out of the engine in the DTS..... on hiway i averaged 28.4 mpg and in town i did 22 mpg!!! LOL

and thank you, The DTS is a okay car. come summer when i put my rims back onto it it will be nicer... The rims on it now are the originals to the 1994 eldo that you see which now has some cragars.



Other than some accessory brackets, and the oil pressure sensor, the 4.0 is a direct bolt in. The accessory brackets just have to be used from the 4.6 and the A/C compressor as well. The intake with fuel rail is used from the 4.6. The PCM runs it with no problems, even passed the emissions test with the 4.0.

I bought it with a 4.0, likely the original 4.6 gave up so thats probably the onle N* they could find at the time. I had a low oil pressure condition with the engine I bought it with, so the only N* I could find at the time, was again a 4.0- did the HGs on it and installed it. One great running car. Just wish it had a bit more low-end torque. I have all kinds of engines now, so when I get a chance, a LD8 or L37 is going back in the car.

Steady cruising with the 4.0 at about 85 km/h (about 52 MPH) I averaged 6.8 L/100 kms or about 34.5 MPG (us gallon) over a 2 hour drive down highway 3 from Aylmer to Leamington, ON.

97EldoCoupe
12-17-08, 05:44 PM
I don't worry about MPG too much either, because WOT is just too much fun! But that is awesome MPG that you got from your DTS- with the L37 and FV4 final drive ratio, I'm surprised it did that well. You must have that car in good tune! I'm not sure my STS could pull off those numbers. In the spring when it sees the road again, I might try a good MPG run.