Foxbody Miles per tank?

GT40 Tubular/GT40X/E-cam with 3.73s, T56, & 275/40/17 Michelin Cross Climates
20-22 mpg to and from work (mix if city/hwy)
Hwy: Typically 24-25mpg. 28 mpg best so far. Think it'll go over 30 if I try.

This translates to 250-300 miles/tank when refilling at the 1/8 tank white line.
I have cracked 400 mi on the highway.
 
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I just did my 3rd fillup in a year of owning my car. If i recall, my trip odometer reading was like 172 miles but it wasn't completely empty. Since i rarely drive my car, when i do, i get 'on it' more often than not.
 
You can't really drive around all the time in vac, though.

I think most here are familiar... :rlaugh:

boost gauge.gif
 
GT40 Tubular/GT40X/E-cam with 3.73s, T56, & 275/40/17 Michelin Cross Climates
20-22 mpg to and from work (mix if city/hwy)
Hwy: Typically 24-25mpg. 28 mpg best so far. Think it'll go over 30 if I try.

This translates to 250-300 miles/tank when refilling at the 1/8 tank white line.
I have cracked 400 mi on the highway.
Dam that's sweet you can put it in 6th gear...for better fuel economy.
 
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Depending on the version of T56, the 6th gear really isn't that much more than 5th on a 5 speed. The T56 for "aftermarket 5.0" applications has a 0.62 6th gear. The T5 has somewhere around 0.78-0.63 5th gear, depending on the version. I was eyeballing the z-spec one (1352-0251) earlier that has the 0.63 OD.
This is what I use a z-spec with 4.10 gears .
 
Depending on the version of T56, the 6th gear really isn't that much more than 5th on a 5 speed. The T56 for "aftermarket 5.0" applications has a 0.62 6th gear. The T5 has somewhere around 0.78-0.63 5th gear, depending on the version. I was eyeballing the z-spec one (1352-0251) earlier that has the 0.63 OD.
0.5:1 6th. 0.74 5th in mine.
 
Yeah... Just bumps up timing about 6* on the WOT table, and more gradually throughout the rest of the timing tables. I worried that it would affect my fuel mileage, but I didn't detect anything.
 
How much hp lost with 87 octane over running 93 octane?

None, if the engine only requires 87 octane.

There is no BTU difference in the two fuels. The 93 contains an additive package that helps prevent compression detonation. Sometimes, a portion of that package includes 10% ethanol. The ethanol will have much larger effect on fuel mileage than the octane rating.


Two pump fuels, one 91 octane no ethanol and one 93 octane no ethanol will be virtually identical in an engine that runs well on the 87.