: Post up your NORTHSTAR GAS MILEAGE (CTY/HWY) PLZ!



fubar569
07-04-08, 03:12 PM
I am having a hard time trying to convince some eh'holes in the corral.net lounge that i can get the mileage i do out of my deville (15-22 city, 28-33 hwy)...

i have intake mods, the exhaust work, synthetic oils, and dexron VI in the trans. tires within 1psi of each other...

post up your best city/hwy mileage and any work you have done to the car or it's state of tune at the time of the documented mileage please...

i know i'm not the only one pulling high 20's / low 30's...

AJxtcman
07-04-08, 03:30 PM
I am having a hard time trying to convince some eh'holes in the corral.net lounge that i can get the mileage i do out of my deville (15-22 city, 28-33 hwy)...

i have intake mods, the exhaust work, synthetic oils, and dexron VI in the trans. tires within 1psi of each other...

post up your best city/hwy mileage and any work you have done to the car or it's state of tune at the time of the documented mileage please...

i know i'm not the only one pulling high 20's / low 30's...

Last weekend I borrowed Highline's car. I averaged 22.3 mpg on the display at 80 mph over an 70 mile trip.
The thing is we have not reset the PCM for the 18" tires. I am thinking it was about 25 to 26 mpg on the trip

Crown Vic Owner
07-04-08, 03:31 PM
32mph doing a constant 45 with cruise on running 5-30 synthetic as well as 87 mixed in with some 100 unleaded (dont ask)

AJxtcman
07-04-08, 03:38 PM
Hey I did a tune for a guy that got about 30 mpg. The AFR/stoich was set at 16.2 as a switching point. The only problem he had was that the trans shifted and felt soft. I guess the map or MAF need to be compensated

Crown Vic Owner
07-04-08, 03:45 PM
What type of car.

It is completely possible in these cars no doubt.

I was making the trip from chicago to milwaukee and took this right after i got over the border.

mighty_quad4
07-04-08, 04:06 PM
2000 STS, avgs 18.5 in town and 26-27 @ 70mph.

though the car is designed to run with tires inflated to 35psi, i run my tires at 42psi up front and 38 out back. anything less and i noticed that the car was riding up the sidewall on the front of the car.

other than that, i just make sure the fluids and filters are good to go and use the cruise control whenever possible. the computer is much better at keeping the car in the 28-34mpg zone when dribing under 65mph than i am.

ryannel2003
07-04-08, 04:15 PM
I get around 17MPG in town, with lots of stop and go traffic. I haven't had a chance to get the car on pure highway yet, but the other day I got 20MPG on 80% highway / 20% city, so I was pleased with that.

I use cruise control whenever possible, and make sure to give it lots of gas unless I need to pass somebody.

Submariner409
07-04-08, 06:09 PM
fubar, When you tally up all the different gas mileage reports, don't forget that the difference between the cars with 3.71 final drive and 3.11 final drive is around 2-3 mpg, with the 3.11 sometimes edging 28-30 mpg, long trip.

My 2002 STS runs 15-19 city/suburban, 18-22 suburban/rural, and 24-26 highway. If I am alone and very careful, flat highway will give 27 or so. (All on 87 Shell, Chevron, Texaco.) I run Pennzoil 5W-30 synthetic, 3,500 miles/quart, and WIX filters. (The 2000 change to roller cam followers had a side benefit from the change to 5W-30 oils: Slightly better CAFE for the 4.6 due to less oil pumping hp loss)

The drivers who insist on running 10W-40 and 15W-40 are costing themselves 2-3 mpg.........

Ur7x
07-04-08, 06:42 PM
fubar, When you tally up all the different gas mileage reports, don't forget that the difference between the cars with 3.71 final drive and 3.11 final drive is around 2-3 mpg, with the 3.11 sometimes edging 28-30 mpg, long trip.

My 2002 STS runs 15-19 city/suburban, 18-22 suburban/rural, and 24-26 highway. If I am alone and very careful, flat highway will give 27 or so. (All on 87 Shell, Chevron, Texaco.) I run Pennzoil 5W-30 synthetic, 3,500 miles/quart, and WIX filters. (The 2000 change to roller cam followers had a side benefit from the change to 5W-30 oils: Slightly better CAFE for the 4.6 due to less oil pumping hp loss)

The drivers who insist on running 10W-40 and 15W-40 are costing themselves 2-3 mpg.........

yup X2 mine is a 2002 STS 3.71 ratio... driven HARD most of its life...90,000 miles on the clock
With the A/C on auto and the car not at all babied I get city numbers on par with Sub's 15-17... cheapo (aka not tier one... like Costco) 87 Octane and 5W10 Old School Oil (what ever is cheapest at Wallmart) and Delco Filters. On the highway it does slightly better then Sub's 27. I usually get 28 MPG (Pilot A/S at 40 psi)

If max mileage is your goal empty the trunk pump up the tires to the max rating on the side wall and turn off the A/C...

Others have other evidence, but I have found no benefit with synthetic oil or 91 Octane gas.

Submariner409
07-04-08, 06:52 PM
Ur7x......Good point: Juggling tire pressures can have a significant effect on gas mileage.

ryannel2003
07-04-08, 07:11 PM
What if your tires have Nitrofill? My dealer insists on putting it on every car we sell, and I have yet to see what it does.

Crown Vic Owner
07-04-08, 07:21 PM
Nothing, its not a formula 1 car.

Submariner409
07-05-08, 09:20 AM
.......The process allows the dealer to say "Mrs. Jones, your car was delivered with nitrogen-filled tires. Now that you're in for your xxx service, would you like us to add a tire pressure check to your service request ?" (Because all this sounds so technical, she'll pay the extra $19.95, which is free $$$ to the dealer.)

Don't forget: Nitrogen is 80% of the air you breathe 24/7/365.

Caddyshack100
07-05-08, 04:57 PM
On a daily 190 mile roundtrip commute, with tires at 30 psi, regular gas, I get two trips up and down, about 405 to 410 miles, and there is about 7 liters left. This is with an 99 Seville STS, at 110 to 115 kph or 75 miles per. I really do not look at MPG but rather the range. Its really amazing what a V8 Engine can do, and look at the new corvette somebody posted about. Of course with Winter driving it will drop about 50 miles on the range.

Harley1973
07-05-08, 05:50 PM
I travel 105 miles a day to work and back on the highway. I only get 21/22. Is that good for a 05 DTS with no mods, Shell or Sunoco 93, 5/30 dino, factory tires 32psi??
What should I change?

Submariner409
07-05-08, 06:12 PM
Harley, How often do you get stuck in the AP/PM jams in Bridgeport, Fairfield, and New Haven ?? Even 3 minutes of crawl will flat kill mileage: A DTS (or my STS) needs to roll for high mileage averages. Is 93 recommended for your car ? Try a week or so with tire pressures set at 35 psi, cold .

Harley1973
07-05-08, 07:48 PM
Sub, I travel CT 395N, RI Route 6 and 295N. The most conjested part is Route 6 with a few traffic lights, I drop about 0.2 in mileage but I'm still able to keep moving. Regular 87 octane is recommended (I think 91 preferred), but I've been running 93 because the car is still new to me. I've got about 27,000 on the odo. About 2 tanks ago I threw in some Techron. I'll try increasing TP to 35.
Thanks,

Ranger
07-05-08, 08:10 PM
Here are the stats from my trip home after purchasing the car in Texas in '06.
Fuel used - 36 Gallons
Avg. MPG - 26.3 (per the onboard computer, 25.8 by my calculation)
Avg Cruising speed - 70
Distance - 930 Miles
Total running time 13:55

Excerpt form post #6
http://caddyinfo.ipbhost.com/index.php?showtopic=10023&st=0&start=0

57james
07-06-08, 10:17 AM
I have a 96 SLS ,If I drive it ,I get 19 city & 25 hwy. if my wife drive's it She gets 22 city & 27/28 hwy. What can I say I love the sound of that mtr. yes the car does have a cold air intake system ,synthetic oil ,slight exhaust mods. & I allways keep an eye on tire pressure ,keeping a good alignment is also helpful. just me 2 cents.

2k Seville man
08-08-08, 04:57 PM
I live in hilly NE PA. 2000 SLS, 123k with absolutely no modifications. Did a test in town - 4.6 mile loop with 33 stop signs - got 18.2. Trip to near St Louis and back to include town driving - 5 people and a trunk full of stuff - no cruise, just paid attention - got 28.5. From home to work mostly highway 1 stop sign and 5 traffic lights, 3 major hills - Avg betwen 29.5 and 30. One trip, took great care (no hypermiler crap) slightly elevation negative - 27.1 miles averaged 34.8. All of these trips were w/o AC. This is a marvelous car. It can reward you in more ways than nearly any other car IMHO. For all those driving econoboxes, get out of the darkness and into the light. Economy and COMFORT in total style -- OMG!!

stoveguyy
08-10-08, 12:05 PM
96 STS. 110k miles. my wife drove it for 7yrs and averaged 12mpg in town. 2 mile trips mostly. i drive it now and go 7 miles to work. 1/2 30mph, 1/2 60mph and i average 18mpg. i don't really do any highway but i see 25 usually. lets see? 1/2 at 12mpg and 1/2 at 25mpg equals about 18mpg average? duh.

limoguy
08-13-08, 07:56 PM
98 Deville...186K, all original. 23 MPG average city/highway. Best car ive owned.:yup:

Splitz300
08-13-08, 10:13 PM
In my Northstar:

80% Highway 20% City driving to work and back : 24MPG @ average 70MPH for the 80% and 45MPH on the City driving.

Hope this is good! :)

jakes95sls
08-14-08, 03:48 PM
my 1995 SLS gets 18 city and 28 highway. I get these on a regular basis and have for the past 10 years that I have had the car. I have had as high as 30 highway without too much load in the car. Most of my highway trips have been from Virginia to Pittsburgh, PA through the mountains too.

MisterBlue
08-16-08, 10:33 AM
My '99 STS (with the 3.71 gears) got around 18-19 in local driving (not really "city" type, block-to-block crawling), but it always got better than 30 on the highway. On a 750 mile trip to Tennessee, I got 32 mpg down, and 33mpg back, driving with the cruise set on 73-77.

My '05 Deville (with 3.11 gears) doesn't do as well, oddly enough. But it still pulls a respectable 19-20 mpg local, and 28 highway. I'm guessing the difference is due to the lower volumetric efficiency of the regular-gas northstar. The weight difference between the two vehicles, being only 100 lbs., is probably negligible. The 1" height difference between the two vehicles would probably account for 1 or 2 mpg at highway speeds.