Re: V8 gas mileage

Posted by PackardV8 On 2010/12/13 22:24:46

Fuel mileage is not all in engine tuning. A great deal of gas economy depends on the rolling resistence of the car AS PRODUCED to specification by the mfg'er.

One private test was ran back in the 70's where comparable model full size V8 Plymouth and a chevy were tested together. The Plymouth with 318 would routinely run 18-20 mpg while the 327 chevy would only get 15-17 mpg all under controlled test track conditions.

The Chevy engine was removed from the chevy and installed in the plymouth. The plymouth still ran in the 18-20 mpg range. I don't know if the plymouth 318 was ever ran in the chevy car or not.

Bottom line: the plymouth according to other testing procedures had a much less rolling resistence than the chevy.