I have seen people asking here what kind of mileage you get with a big cam, ported heads and headers. This weekend, I made a road trip, so I measured it. I got about 22 mpg over the whole 300 mile trip.

Most of it was freeway driving at 75-80. I am still running the stock 3.43 rear end, so I made the whole trip in 5th gear. That means I was turning about 2600 rpm all the time.

I could probably have gotten better mileage numbers in 6th gear. The car just feels sluggish in 6th at about 70, so I rarely use it. I think I may be able to get the numbers up to about 24-25 mpg with a 4.10 rear end, so I can acually use 6th gear.

I haven't kept track of the mileage around town, but it's probably not great. But then, who buys these cars for gas mileage anyway?

BRAD

 

not bad, I'm sure in 6th you'll get more. Not sure if the 4.10s would help, with mine I'm at 2400 rpm at about 80, before with my 3.42s I was at 2500 rpm at 100 mph 1900 at 85. I haven't really noticed a difference with mileage if I keep my speed down, and if I lay off the gas, If I do any of the two mentioned I don't get crap for mileage. Do you get any surge in 6th at say 70-80 mph with that cam? Cops every look at you funny rollin with that setup in LA

 

i was getting about 24mpg with 4.10's all hwy driving in 6th gear..

 

you are weird...............why dont you just use 6th................for highway cruising you want the rpms as low as possible

with 3.42, my 6th gear at 80mph is about 1800 rpm.......gets great mileage

 

I get a little over 20 on the highway and 13-15 city. That's an auto w/ a vigi stall, p/p heads, and that cam.

 

I go about 160 miles to a tank of gas on my XE 230/236 in the city with 3.23 gears on a 700R4 auto tranny.

 

daaaamn........that sucks..............and here i thought my gas mileage was bad

 

13 in the city, don't know about highway.

 

I'm also a 383.

 

"I go about 160 miles to a tank of gas on my XE 230/236 in the city with 3.23 gears on a 700R4 auto tranny. "

Ditto that, and im also a 383, however, I am still dunning bone stock tuning. I expect a big improvement once I get the PCM tuned.