Trying to get my MPG back...

[slooowr6]

On my 2600 miles trip to Yellowstone, I notice drafting helps my MPG. I don't mean like tail gating, I can see the number change on my Scanguage just by staying 100 feet behind a big RV, truck or even a car. I usually stay about 3-6 seconds behind them.

 

[Martinjmpr]

had a couple tanks since this thread started and getting my gears broken in and I have been keeping a close eye on my MPG. Thought I would add my experiences and add some other factors.

Information about the truck:

86 4Runner with 22RE.
My truck is running 33x12.5's BFG AT's with about 27 psi to keep the tread wear even (skinny 7 inch rims).


Recent rebuild on the engine and transmission. Synthetic in tranny.
The truck has been regeard to 4.88 and that adds about 1 mile for every 100 traveled and confirmed with a GPS.

One tank had a fair amount of hwy and I live in Atlanta and travel the Atlanta Autobahn so 65-70mph is the norm. At those speed truck alone I am getting right at 21mpg.

Actually 21mpg sounds pretty good given the size of the tires. My dad's old '88 4runner, bone stock with the small stock tires rarely got above 25, so I think you're doing alright. Not sure how much better you could reasonably expect.

 

[Pskhaat]

Mythbusters concluded that running without AC sucked much more gas than windows down.

Yes, I saw that episode and the myth itself that was busted was that windows down == AC. Their test showed AC consumed significantly more fuel than windows down.

In my little commuter beater, I have a ~7mpg difference between windows down vs AC! 28 vs 35. at normal highway commuting. That non-linear increase in drag with respect to speed is obviously vehicle-specific, but even in my 80 I notice much better highway (65mph+) mileage sans AC.

Needless to say I keep the windows down but right now at 110F+ it's getting brutal.

 

[Grim Reaper]

Actually 21mpg sounds pretty good given the size of the tires. My dad's old '88 4runner, bone stock with the small stock tires rarely got above 25, so I think you're doing alright. Not sure how much better you could reasonably expect.

I really haven't had one solid tank of Hwy. I just filled it Monday and it Got 20 MPG but that included about 18 miles in Low on some REALLY steep trails that pegged the tiltowhirl meter quite a few times. 200 miles of hwy and weeks worth of commuting.

Might be making a 250 mile round trip of hwy this weekend. See if I can get a good solid Hwy reading.

So far I am not upset about the MPG. Next set of tires may be 10.5's to cut down the rotational weight and some of the extra rubber I have on the ground....But I really like how it is doing on these tires and how it looks. :arabia:

 

[Grim Reaper]

Yes, I saw that episode and the myth itself that was busted was that windows down == AC. Their test showed AC consumed significantly more fuel than windows down.

In my little commuter beater, I have a ~7mpg difference between windows down vs AC! 28 vs 35. at normal highway commuting. That non-linear increase in drag with respect to speed is obviously vehicle-specific, but even in my 80 I notice much better highway (65mph+) mileage sans AC.

Needless to say I keep the windows down but right now at 110F+ it's getting brutal.

My company van is a 07 full size Chevy with AWD 5.3 and 3.73 gears. It gets better MPG with the windows up and A/C on then no A/C windows down. I am actually quite impressed. Its getting 17.5 consistently and thats carrying 400-600lb of cargo. It gets better MPG by 1 MPG then our other company truck (05 Z71 with 5.3 and 3.42 part time 4wd and a smooth Aluminum ARE shell) with the same cargo load.