Re: V8 gas mileage

Posted by Loyd Smith On 2010/12/19 13:08:06

What 55PackardGuy says about the 13 mpg(US) is basically true.
I am no longer using my 55 Pat as daily transport but, for the approximately three years that I did, I found that it would average about 13 mpg consistently in combined city and highway driving on trips back and forth from Orlando to Miami, driving in fairly heavy traffic with the A/C running most of the time. My best highway mileage would run 16-17 mpg at approximately 3650 rpm (where I found that mine 'wanted' to run). At various times I monitored this with both a vacuum gauge and an electronic tachometer. With my multi-spark ignition setup, using stock points as breakers, I was able to improve upon this slightly - but not all that much.

My recollection is that this average 13 mpg was pretty much standard for large luxury cars of this era (except of course Chrysler Imperials). Even up through the 70s all of my full-sized Caddys averaged about 13 mpg - whether tuned or not, tires properly inflated or not - whatever.