28Q29U Plymouth Forum

General Category => General Discussion => Topic started by: SteveG on December 12, 2013, 10:06:16 PM

Title: Gas Milage
Post by: SteveG on December 12, 2013, 10:06:16 PM
Got my '28 business coupe on the road. Original Maxwell 4 engine and driveline.

I as wondering what kind of gas mileage are you guys getting?

SteveG
Title: Re: Gas Milage
Post by: frankp on December 13, 2013, 09:21:19 AM
Steve,

I got around 10 mpg in 2002.  When I've traveled 100 miles, it's time to stop for fuel.

frank
Title: Re: Gas Milage
Post by: SteveG on December 13, 2013, 05:34:14 PM
Frank, I haven't had a chance to figure out what the GPM is, but as fast as the gauge went down I knew it wouldn't be great.

Are the rest of you guys experiencing the 10 MPG?

SteveG
Title: Re: Gas Milage
Post by: Old Man on December 15, 2013, 11:47:03 AM
10 is a little low. They are all crappy through the 20s and 30s,compared to even the 50s, but I'd expect more around 15 mpg. Possibly even a bit more. Make sure the plugs are staying clean/light brown and not sooty. That's the only practical way of determining if one of these old engines is running approx. between lean and rich.   
Title: Re: Gas Milage
Post by: frankp on December 15, 2013, 03:33:00 PM
Old Man,

That confirms my thoughts.  Put in new plugs this summer and all the old ones were very black.  I'll have to check these plugs next spring.  Currently there is binding somewhere in the carb throttle linkage that prevents it from returning to idle position without a foot assist on the pedal.

15 mpg would be amazing.

frank