Impala Tech - View Single Post - Poor fuel mileage
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post #3 of (permalink) Old 08-28-2019, 08:48 AM
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Join Date: Dec 2012
Location: virginia
Posts: 386
Originally Posted by ImpalasDave View Post
I have an original 64 impala base model with a stock 327 all original. Rochester 4GC carb.
I’m getting 9-10 mpg. I’ve been told that’s about the best I’ll get because it’s just old. It runs, drives, and starts cold just fine. No smoke. Idles nicely. Seems normal and smooth. Drives nice and normal as well. Doesn’t have any punch but it’s just stock. Should I be getting better mpg? What can cause low fuel mileage? And were should I start?
Thanks for any advice.

Not because it's 'old'. With today's gas, that sounds about right for 'around town'. 'Highway' 14 or so. A 10% ethanol mixture reduces mileage by about 15% (my experience).

My '63 Impala 283 2 bbl (in 1968) used to average about 16 but that was almost 90% 'highway' and gas w/o ethanol. It was a 3 speed manual w/3.36 rear.

Gear ratio and driving 'style' impact mileage too.
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