Your best highway MPG?

evanandretti

Full Access Member
Joined
Jul 11, 2010
Messages
566
Reaction score
0
After I put my magnaflow catback on I was seeing if i got better gas mileage,

I hit 22.3MPG flat road and steady.

Seems way to high? I'm not complaining but have you guys seen those numbers?
 
After my 6 speed swap I average about 13.5 city and pulled an 18 MPG on a 250 mile round trip with the A/C on half of the trip! WIth the auto I was at 12 city and maybe 13.5 highway.:rock::rock::rock::rock::rock::burnout:
 
never... best i ever saw was 17.5 running 70 on the dot with the ac off for 30 miles on hwy 10
 
Just got back from a 600 mile roundtrip from DFW to Stillwater OK (HS baseball tournament)... I was typically right at 78-80mph... averaged 16.5 on the computer... not sure if that is accurate or not, but I didn't calculate it myself. That's the first time I've had this truck on an extended highway run.

Truck is near stock... minor bolt-ons.

Should have said, A/C was blasting the entire trip... it was 106-112^. I think if I'd been averaging 65-70, it would have done better, of course.
 
Last edited:
17.4 going to the ocean before bunch of mods tho.
 
A couple trips to LA from Phx and back I averaged 18.5mpg. If I backed speeds down to 65 I managed around 21mpg.
 
Oh I also had an argument with my girlfriend about AC sucking gas mileage. I told her that it wouldnt make a noticeable difference. And i'm not sweating my balls off to save a few cents.

So we reset the computer on the high way at all different speeds and the AC didn't even bring it down a point. I assume these big motors would barely notice the compressor cutting in and out? True story or is my girlfriend right??
 
Are most of you guys going off what the overhead says or doing the actual math? The best I've seen (actual math) is 13mpg. Going to change out my o2 sensors and see if it helps.
 
Oh I also had an argument with my girlfriend about AC sucking gas mileage. I told her that it wouldnt make a noticeable difference. And i'm not sweating my balls off to save a few cents.

So we reset the computer on the high way at all different speeds and the AC didn't even bring it down a point. I assume these big motors would barely notice the compressor cutting in and out? True story or is my girlfriend right??

You are very right my friend. And its accually been proven itll waste MUCH more gas to role the windows down because of the drag from the wind. A/C will really only kill gas mileage while doing city driving, but driving on the highway and going faster then like 45-55mph with the windows down will kill your gas mileage
 
My test was in december when i sold it so no AC needed. Actually it was on the way to drop the truck off to the new owner. It was good to have that number on the display.
 
The overhead computer calculated the LB/hr of the injectors at the specific fuel pressure and the amount of pulse width modulation load the injectors are on divided by the distance traveled.
So its measuring how long the injectors are open, and how much fuel would be spraying through them at the factory rated lb/hr.
 
My mileage is way up since we did the cam. I haven't done a long road trip yet, but I am getting 25ish on the freeway, 110-120km/h in 6th. It's the range I'm getting on a tank of gas that is so noticeable.:)
 
My 18 mpg was accurate as I did the fill the tank up, reset mileage, fill up when needed and do the math on the gallons used versus miles traveled. Mine was an average of 73mph. It totally agrees with my overhead. A few naysayers said it was due to the QC PCM running the T56? Well I eventually put in a RC PCM and exact same results!!!:rock:
 
2333857d.jpg


Of course, I was going down hill and had a bit of a tail wind, but for about 30-45 seconds I had a 10 with better gas mileage than a Prius
 
Back
Top