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For the first time, my '00 broke 30mpg. My drive to work and back is about 110 miles.

It could be the warmer weather (90's here the last few days), summer blended gas, who knows. I did gut the intake and replace the air filter the other day with one of the K&N knock offs (Spectre?), and the O2 sensor about a week back, but I can't see that making a huge difference.

Anyone else see that kind of mileage on their car on a regular basis? Or is this just a freak accident?

It's normal. My old Bonneville once did 35 MPG. I kid you not but that was once however it regularly pulled down 30-31 MPG with a 18-yr old teen (at that time)

Now I'm driving a turbocharged Saab that's pulling down 34 MPG with possible 36 MPG in the future, been trying to get there. Totally irrelevant yes but I had to share.

I regularly see 28-30 mpg this time of year from my LeSabre in my normal driving. Last tank was 30 mpg.

Driving style plays a huge role with these cars. They love to waste gas at any opportunity.

My best tank ever has been 25 MPG. Part of it is that I'm 19 and drive accordingly, but I feel like there's something goofy with my car...

00Beast wrote:My best tank ever has been 25 MPG. Part of it is that I'm 19 and drive accordingly, but I feel like there's something goofy with my car...

I'm sure you've already considered this, but FWIW, my DIC said 25mpg avg for that tank, calculated was 30.1. Usually the DIC is only about 1.5-2 mpg lower than actual.

My DIC is always HIGHER than my average. I also calculate EVERY tank, lol. Look in my sig for more info, lol.

The DIC is notoriously inaccurate on the 2k's.

Use your calculator and what the pump and odometer say. Then try to beat my 33mpg averaging 70mph over the Siskiyou Summit into California.

What I typically get for highway milage in my SLE is what the window sticker says.. 28 MPG. Otherwise I get 24 - 25 MPG average. No mods to the car.

00Beast wrote:My DIC is always HIGHER than my average. I also calculate EVERY tank, lol. Look in my sig for more info, lol.

Weird. My DIC always calculates a little below. I reset it each tank but it usually reads between 22 or 23. My average for all the driving I've done (granted I've only owned the car in winter and some spring, which nets poor gas mileage) has gotten me about 22-24 mpg average.

The table I posted below is the most recent fillups. I keep track on http://www.stlouisgasprices.com (http://www.gasbuddy.com).

PRICE GALS COST MILEAGE

5/11/2011 4.059 15.369 $62.38 116,610 Phillips 66 Y 30.29
5/8/2011 3.959 2.148 $8.50 116,258 Phillips 66 Y 22.90
5/6/2011 4.049 4.322 $17.50 116,225 Phillips 66 Y 15.36
5/5/2011 4.049 4.816 $19.50 116,116 Phillips 66 Y 25.22
5/4/2011 4.049 5.929 $24.01 115,997 Phillips 66 Y 24.71
5/3/2011 4.249 7.534 $32.01 115,857 QuikTrip Y 23.61
5/1/2011 4.039 14.487 $58.51 115,714 Hucks Y 18.98
4/27/2011 4.119 8.743 $36.01 115,372 ZX Y 23.61

My DIC is always within 1mpg, and most typically within 0.5mpg. I can pull 27 out of the Northstar on 87 octane (it's rated for 24 highway by the EPA), which would be the same as running 30mpg in an SSEi on premium, financially speaking.

My record is 34 fat I did once, but like ed my car doesn't seem happy lately and has been below 20 mpg

willwren wrote:The DIC is notoriously inaccurate on the 2k's.

Says who? Both mine and Shannon's are spot on. "FUEL USED" is within 1/10th of a gallon when filling up.

willwren wrote:The DIC is notoriously inaccurate on the 2k's.

Use your calculator and what the pump and odometer say. Then try to beat my 33mpg averaging 70mph over the Siskiyou Summit into California.

I've seen a DIC be any where from 1mpg to 3mpg off. It's usually in favor of the car, but it will on occasion be lower than what the car actually got. The worst fuel mileage we've gotten on any car we've driven in the last 8 years was a 2010 Tarus Limited and it lies so bad that it was of no value in my opinion. It was even worse than the wife's CTS in fuel mileage and accuracy. The best we've had was a 2004 Impala with a 3.4L in it. 36.1 on the interstate, 33.6 combined and the DIC was pretty close. - BC

harofreak00 wrote:

willwren wrote:The DIC is notoriously inaccurate on the 2k's.

Says who? Both mine and Shannon's are spot on. "FUEL USED" is within 1/10th of a gallon when filling up.

Says most of the members in this topic. I would consider 1 or 2 mpg inaccurate. That makes a 28 look like a 26. That's a big chunk.

Before I did a tune up on the Ultra, it had its original plugs and wires at 135k..and was giving me 28mpg on the highway, 20 city. Then, I did Delco wires and TR55s, and now it won't go above 23 mpg highway, and averages 19.9.

My step dad is reporting 33-34 mpg at 65 and he takes his 2004 SLE to a shop for most of his work. I was impressed by that. He checks his mileage manually as well.

That's the mileage I get averaging 70-75 on the freeway. It may sound like stretched truth to some, but I've found the more power I build into the car, the better it does on the freeway, and the worse it gets around town (about 12 average). The key, I think, is the fact that its so easy to add low-end to the Series 1 L67. When I'm cruising in OD, I'm deep into my torque curve, so the car doesn't have to work very hard to maintain speed. That mileage has been logged on 2 consecutive trips to Northern California, a 600 mile or so trip over the pass. Long runs, few stops. The return trip drops 1 or 2 mpg due to the crappy California fuel blends.

I once got 33 with the 97 SSEi with 4 passengers and all their luggage, interstate @ 80 mph. I left Denver and didn't touch the pedals for 250 miles. I know my mileage takes a hit after 70, so I can only imagine what it would have gotten doing 65 or 70.

Running on a 2 lane highway @60 Mph Cruise set... 2003 SLE



On my way home from WV, I was doing 80 MPH on I-95 and was doing 29 Mpg.. DIC was spot on for my WV Trip

harofreak00 wrote:

willwren wrote:The DIC is notoriously inaccurate on the 2k's.

Says who? Both mine and Shannon's are spot on. "FUEL USED" is within 1/10th of a gallon when filling up.

I didnt believe it until I got my fuel guage fixed, and I found it it was nearly identical. However, if you let you car run at idle for a period of time, it will affect the DIC reading accuracy.

My highest reading so far is 30.1, but it was no wind & on a flat road. Usually I get 27 on the highway & around 17-18 in the city. About 21 on my daily commute (60/40 city/highway). Thats if I dont use my 19 year old driving style lol.

Lately since it been nice & warm up here (which means I become 19 again ) Ive been averaging around 18-19.