Specs - Fuel usage MPG

AUSSIEVETTEMAN · 05-09-03, 05:56 PM

Does anyone know what the original figures are for the fuel usage for an 81 Coupe?

Thanks in advance!

Eric · 05-09-03, 09:58 PM

I got this from a pretty obscure web page but at least it was out there somewhere

. The report states an average of 14 for the manual tranny and 15 for the auto.

page62 · 05-09-03, 10:32 PM

Woohoo! It claims that my '79 gets 16 mpg. These figures must have been calculated going downhill with a strong tailwind at 35 mph!

MaineShark · 05-09-03, 10:37 PM

Quote:

Originally posted by page62
Woohoo! It claims that my '79 gets 16 mpg. These figures must have been calculated going downhill with a strong tailwind at 35 mph!

My '79 gets 16.4, driving in a fairly "spirited" manner. Having a guy who is familiar with the C3's do the tune-up did wonders for the mileage. I was getting under 15, before. And there was a noticeable power increase after the tune-up, so I think he did a good job

Joe

LEEJANDZ · 05-09-03, 10:40 PM

I will trade with any of you.
I am averaging about 8 MPG in my 79 L-82.

JASON *** BRAND NEW 350 cid GASKET SETS FOR SALE!!! *** 1979 L-82

Eric · 05-09-03, 10:42 PM

Quote:

Originally posted by page62
Woohoo! It claims that my '79 gets 16 mpg. These figures must have been calculated going downhill with a strong tailwind at 35 mph!

What do you expect, afterall it is a government website

.

- Eric

AUSSIEVETTEMAN · 05-09-03, 11:05 PM

Thanks guys.

15 Miles per gallon hey, well that's about 6 miles per gallon more than what I calculated this morning.
I filled the tank up with 28 Litres this morning (around 7.5 US Gallons) and she had done 70 miles.
I don't know if that is good or not?
The carby is not stock, it is a Holley 650 double pumper. When it runs, it runs pretty 'sooty' just idling (no smoke when you nail it), leaving soot marks on the driveway. I think the Holley maybe dumping too much fuel in there at idle and maybe limiting performance when I nail it, as the original Rochester from the information I have gathered, is around 795 CFM, where as the Holley is 650 CFM.
Maybe it's time to change the Holley for the Rochester!

JohnZ · 05-10-03, 08:01 PM

The EPA estimated fuel economy numbers are generated based on a very carefully-orchestrated EPA-mandated test sequence on a chassis rolls dyno which bears little similarity to the real world (after all, it was invented by Federal bureaucrats, right

); that's where things come from like the 1st-to-4th skip-shift system with the "shift light" that started on C4's, to "optimize" the test results. Like it says on the window sticker just below the EPA fuel economy numbers, "Your Mileage May Vary"