View Single Post
Old 05-02-2013, 02:53 PM   #88
TommyDuncan
Registered User
 
Join Date: Feb 2013
Location: Boulder City NV
Posts: 214
Re: 1966 GMC 305 V6 Service

Quote:
Originally Posted by Rufton View Post
I'm very curious about the mileage also. I log mileage every fill. I put smaller main jets in worn out 305E last year and improved hwy mileage from 10 mpg to 12 mpg. The compression was so low and oil consumption so high I was surprised it didn't foul plugs. I hope the fresh 305E will do better. My gear oil in rear and trans may be too heavy for mpg; I'm thinking of switching to lighter gear oil.
I expect initial readings to be low because not fully broken in.

Guess I should road trip to get mpg data faster
thanks for the reply. What rear end gears are you running?

A friend of mine had one of these and swears he got 7mpg no matter what. He also said it was geared to low for much hwy use. After looking at their low rpm torque curve I wonder if it is necessary to gear them that low?
Posted via Mobile Device
Posted via Mobile Device
TommyDuncan is offline   Reply With Quote