In about two weeks I am getting a decent bonus check, so guess what I am planning to buy when I get it.
To appease the "better" half, I was wondering what is the highway gas milage some of you have been getting with the LT1 and 6 speed, and the LS1 and 6 speed.
I thought they were around 24 to 26 miles to the gallon. Please let me know if I am off base, or I am close.
Thanks in advance.

I saw close to 30 when my 98 was mostly stock

Thanks Mitch.
That makes the wife happy.
The next purchase is going to be a multi-purpose vehicle. Daily Driver for work (Beloit to Madison), weekend cruiser, and now that I have permission from my Doc, a track day or two to take care of those wild hairs.
Now the hard desicion, Z-28 or Trans-Am.

Easily 25+ highway for pretty much any 6 speed 4th gen. The LS1s do get slightly better mileage, but not by much. Where you'll run into trouble is city mileage, especially if you start modding the car.

Stock mine 01 was 28+-, Tuned 30.5.

Miss it really bad

John

Saw 29.5 once, fully loaded and only driving 70 in a 65. Typically get 27/28 on the road, depending on elevation changes and traffic flow. Have not taken a road trip since updating the exhaust and tune though. LS1s get better fuel mileage IIRC.

When my 01 was stock with 16" wheels, I could get 30 to 32 on the interstate if I drove carefully.

It does depend on how deep you put your foot into it!

My stock 98 (LS1) could get a hair over 30 on the highway with gentle driving.

My slightly modded 97 (LT1) with 3.73 gears gives me about 24 with not completely gentle driving.

I got 28 mpg last summer on a trip from Pittsburgh to South Carolina. And that was going through the mountains. When I went to Solo Nationals in 07, I managed 24 mpg towing a 4'x8' trailer loaded with wheels/tires, a giant (loaded) 2'x4' tool box, and all our luggage. All of that was in 6th gear with the cruise set at 70-75 mph. Commuting back and forth to work usually gets me about 18-20 mpg, driving it pretty easy. I'm sure I could get single digit gas mileage out of it if I tried.
This is from a completely stock 94 LT1/6-speed.

That's what we average for complete trips ... with 4.10's in an LS1 ragtop.

A few years ago I have gotten 28 to 30 mpg on the highway driving from Chicago to Cleveland and back. However, when I used to drive it to and from work once in a while on nice days, I only got 14 mpg. By comparison, my 2005 Yukon averages 17 mpg going to and from work.

So in other words, it's possible to get really awesome millage, but it's also possible to get really crappy millage.

Trans Ams get an average of 40mpg, while Z-28s only get about 6.

Of course, I may be biased.

Almost. My wife gets 13 out of her 94 vert. Oh wait, it has a 381 with ALMOST too much cam. A friend with a FS-legal Firebird got 30+ out of his 6-spd, and 28 towing his LaCasita trailer.

My cruise control was broken, but it appears I managed 30-32mpg driving the speed limit coming back from Sebring a few months ago.

http://www.hptuners.com/forum/showthread.php?t=20882

City driving, er, well, that's usually 12-15MPG. Now that it's mostly drivable in 6th gear down to 1000RPM, I suppose I could get more out of it if I tried... but where's the fun in that?

FYI - I got better mileage out of my 2000 Trans Am than in my 4-cyl Saturn Ion (about 22mpg) or my G8GT (about 20mpg).

Both those figures are driving 100 miles per day, 20 miles city and 30 miles interstate, no traffic. The 4-cyl got bad mileage because I floored it at every stoplight because I was used to going a certain speed and accellerating at a certain rate.

Thanks to all who have chimed in so far.
I have about 1 mile of 40 mph, than the rest of the 56 miles one way is I 90- and Madison's "wonderful" Beltline.

Mostly stock, 28-29 mpg on the highway averaging about 80 mph whileon the road.

headers cut the mileage, gears, and cam got me down to 24 or so. Driving locally is where it really hurt. dropped from over 20 to somewhere around 16-17.

If you can find a ws6 1le formula, buy it. If not, go w/ an SS.

Or the Holy Grail, which you see on craigslist first.

From Columbus, OH to Morgantown, WV with 2 people in the car (2002 Z28 M6) and a weeks worth of luggage, we saw 29.5 mpg with the cruise set at 80mph for most of the trip (there was a little traffic leaving columbus that was "slow down, speed up, slow down, speed up" for the first 40 miles or so).

Dallas to Miami, running 80-85mph, no cruise control, 3.73 gears. 24mpg.

Mark

In my CMC LT1, during a 40 minute race at Texas World Speedway, I'm getting about 7mpg ...

Wow, that's just like commuting in my truck...

As a side note, my 2000 VW GTI VR6 was showing 6.2 mpg at 140 mph based on the instant fuel economy computer display.

Oh, your in Beloit. Then by all means, get a Pony car and come to Milwaukee to autocross it during the weekends. We have a nice little friendly group of F-bodies and one wayward Mustang driver who would enjoy the addition.

There was an NBM one on ebay a few years ago w/ very low mileage.

If my local Pontiac dealer wouldn't have given me so much crap about a 6 speed, that't what I would have ordered.

During HDPE's, I usually get much better mileage than many smaller cars too. (Still only 7-10 mpg). R32's and turbo cars are pigs on fuel.

LOL my 383 stroker with Tremec 5 speed and 3.23 gears gets 22-24mpg on the highway. It got 29-30mpg before I re-tuned it, it was so lean that it was surging, bucking, and trailer hitching.

All my buddies have LS1 6speed cars and they all get 28-30mpg on the highway.

what was their deal? Automatics suck.

More warranty work for the dealership?

Are you with Midwest F-Body, Midwestern COuncil of Sports Car Clubs, or some other organization?

I race with both the Chicago and Milwaukee SCCA, WAI and TSSCC. So between all four clubs there are 32 possible events in the Chicago/Milwaukee area. The Milwaukee Region and WAI both use Miller Park exclusively for all their events.

They were probably afraid that if he ordered it, and then didn't take delivery, they'd be stuck with it. Since they _really_ didn't understand what the car was, they didn't have a clue how to properly market it. But that's just my thoughts.

Some pretty similar results... I can easily get 28-30 MPG doing all highway driving, keeping it around 75. We drove back from Yellowstone recently, going 70 MPH except for when we went through some small towns. I managed to get 32 MPG.

And 7-8 MPG in a truck? Ouch... My wife's new 2500 Sierra (gas) gets 13.5 city driving. She could probably do better, but she's been developing a bit of a lead foot.

I kept detailed records on my last '98, and have >31k miles of data. It averaged 22.5, and they will easily get 28 on the Interstate with a 6-speed and cruise control on.




http://www.cleanmpg.com/index.php?page=gar...mp;viewcar=1912

Normal combined driving of Autobahn and city is about 20 mpg . Track days and high speed Autobahn driving equals 4.5 mpg.

My '02 M6 Z-28 gets 30 MPG highway in 6th, 24 MPG towing small utility traier w/ tools, tires, and spares, and 4-5 MPG at WGI. Economy performance car is not an oxymoron.

That was really a joke. My '77 3/4 ton Chevy ("no" compression and a 2bbl carb with 4.10's) got about 8 mpg, my current truck gets about 11.5-12 average and a best of 13.5 highway (once).

In my '99 Z28 M6 hardtop, in 3 trips to Houston, I got just a "tick" under 29 MPG from Arlington to Houston (300 + miles) avg 75 MPH with AC on about 1/2 the time .........pulling a tire trailer ! !

......the only mod were F-stock mods

The lifetime fuel mileage for my 2000 Z28 6 speed was 21mpg... I owned the car for 30,000 miles

Starting with a full tank, I went through ~18 gallons of fuel in about 80 minutes of racing. The car now has about 1/2 a tank according to the fuel gauge.

On another note and sorta OT because the trailer had my F-Body in it ...
The 07 PSD bone stock pulling my 28' enclosed weighing in at ~9K got 11.1 going to MSR-Houston this weekend (some head wind and traveling 65-75) and got 12.9 on the return trip, same speed, but mostly a strong tail wind.

Ha, I'd kill for that kind of towing mileage...

I got 30 mpg on the highway in my stock LS1 Camaro before our gas got watered down with Ethanol. Now I get about 17 city and ~25 highway (lots of rolling hills). Wife's Honda Civic used to get 35mpg before the fuel switch and now gets 32mpg mostly highway.

Oh, you have an 8.1L engine in your truck too?

People did't want to think about it? Just write the order, or sell one off the lot?

On a side note, when I went to Phoenix Pontiac (you guys know them, right?) I was trying to get pricing on a 2002 Formula Firehawk, since they didn't offer WS6 formulas any more.

I was told 3500 non refundable deposit. I just walked out.

I hate ethonal.

I found a place way out in the boonies passed madision WI by my parents house that still sells straight gas and it is $0.10/gallon cheaper than the Ethonal crap. I started bootlegging gas back to IL via 5 gallon fuel containers every time I go visit my parents.