V8 Guys Highest MPG

[pantsman]

2004 LS V8 (K&N Drop in, otherwise stock)
mid michigan to cinci and back (about 660 roundtrip)
25.5 onboard computer (people still do this by hand?)

regularly in city 20ish, my new route is getting almost 21
highway average 23.5 or so, the one time i did reset just as i entered the freeway i was getting 26.5

when i see you guys getting sub 20 i have to ask are you using high octane gas? when i bought mine the dealer was nice enough to fill the tank with 87 octane and mileage was terrible. i never got over 18.5 anywhere. with premium its a whole different story. also check your tire pressure and your air filter because damn anything under 18-20 sounds like a problem

 

[KC_Steve]

I am using nothing below 91 octane, and generally 92 octane. I try to find a BP around here, because they offer the 92 octane. Still, I am averaging only 16 city and 21 highway. I want to get on it once in awhile, but I don't because I know what the outcome with me.... worse mileage. I have had the car a couple months now, and have only gotten on it 3 times.....

 

[Drnaline]

Had to be draftin.

At 65, there are not many people to draft but i know what your talkin about and it does help. I do use a technic for economy. I will try not to give it gas unless I am on a down hill, i will use that down hill to gain some extra speed before I hit the next one. When i am climbing up that hill i will gradually decrease speed, trying not to maintain a particular speed. Then upon cresting I start all over again. The car seems to like it at 65/70, I'm sure i could get better if i found some one that drives like that to draft behind? At 75/80 i get an average of 29/30 MPG. Can't wait to see how a K&N will help.

If your conscious of your driving habits there is MPG to be made. Using cruise it not it unless your drafting. I anticipate better as i modify the exhaust and intake system. I'm trying to save up some bucks now so i can buy some exhaust manifolds to play with. Port and polish. I found some used cylinder heads but they want 550 a piece for them. That will take a while. My bird i have had since 90' (it's and 89) I managed to get it all the way up to 37 MPG in certain situations. It is a supercharged V6. I massaged the hell out of the SC, intercooler, exhaust manifolds, intake and heads. All stock parts, cam, and computer, with a custon intake tube and K&N. Have never had it dyno'd though. Recently i just heavely modified the front end to install a intercooler from a powerstroke, not for the faint of heart, LOL Got some pics at Photo Bucket from my cell phone. If i can figure out how to post images, I'll post some if any one is interested.

 

[Fastbird]

At 65, there are not many people to draft but i know what your talkin about and it does help. I do use a technic for economy. I will try not to give it gas unless I am on a down hill, i will use that down hill to gain some extra speed before I hit the next one. When i am climbing up that hill i will gradually decrease speed, trying not to maintain a particular speed. Then upon cresting I start all over again. The car seems to like it at 65/70, I'm sure i could get better if i found some one that drives like that to draft behind? At 75/80 i get an average of 29/30 MPG. Can't wait to see how a K&N will help.

That's a great technique. It's how I managed 425 miles out of a tank moving at a near consistent 80 MPH while going through WV.

If your conscious of your driving habits there is MPG to be made. Using cruise it not it unless your drafting. I anticipate better as i modify the exhaust and intake system. I'm trying to save up some bucks now so i can buy some exhaust manifolds to play with. Port and polish.

I'd LOVE to see someone come up with headers for these things. There's a TON of room up there for some good mid-length headers, and possibly even enough room for a full blown long tube.

 

[02LSE96LSC91SE84TC]

I am aware of the driving habits you describe, and also know cruize isn't efficient because it does not have this ability. However with other people on the highway, not crowded, but others on the highway going the same direction, that kinda inconsistent speed is annoying. I seldom drive any real distances where I could try to maximize this way, always people in front or back, plus slowing to 45 rather than stepping on the gas for a hill most aren't going to do. Your mpg is impressive, many probably will doubt it.

 

[Drnaline]

Fastbird

I'd LOVE to see someone come up with headers for these things. There's a TON of room up there for some good mid-length headers, and possibly even enough room for a full blown long tube.

Your right, i think there is plenty of room under there. I've looked at it extensively from the bottom, although a tight fit for it to hook into the stock exhaust. I don't think it is impossible. I believe what would make it the hardest is the studs for the manifold mounting, i think it would be an easier instll if it were converted to bolts. Which would be a harder job for the end user. That would be the hardest i think, fabing a header while leaving the studs = no fun, LOL. But sooner or later i'm gonna tackle it.

02LSE

plus slowing to 45 rather than stepping on the gas for a hill most aren't going to do. Your mpg is impressive, many probably will doubt it.

I usually don't slow down lower then 55/60 max. I'm not doing it to impress any one. Less money spent on high test means more in mods. I don't think it's that impressive anyways. It was almost exactly what the factory miliege called for, 28. I got roughly one-one and a half more by drilling the air box. I believe the rest can was obtained by a combination of trying to keep a lower average speed while using natural terrain to aid such a heavy critter.

 

[02LSE96LSC91SE84TC]

I've seen 17/23 listed and 17/25 also, and I remember someone saying the newer models were 26. I've never heard 28.

 

[Drnaline]

I've seen 17/23 listed and 17/25 also, and I remember someone saying the newer models were 26. I've never heard 28.

The salesman said 26/28. I guess i just got a good one.

 

[bronco_ls]

350ish mile
85 - 90 MPH
avrage 25.8 MPG (by the onboard calculator)

 

[Dutch]

48,000 miles. 60 miles jont from Santa Fe to Albuquerque. All stock 01 LS8 except for drilled air box. 33.4 MPG @ 65/70 MPH.

Keep in mind this is based on the very optimistic computer, and remember this trip is all downhill.

I got 30 mpg once (measured mathematically) going from Gallup to about Holbrook in my Chrysler, but I sure wouldn't say that car gets 30 mpg.