1966 GMC 305 V6 Service

[factorystock]

Originally Posted by Rufton

Thanks for the compliments.

I took the GMC 305E on an I-75 trip 3-4-14 and got 13.4 mpg and 14.1 mpg driving approx 70mph. Need to get her out more but I've been tied up.

Old post yes, but, there are plenty of V6 owners out there that might find this old post and this article I found recently interesting. Mileage reported by Rufton is almost indentical to the owner of the GMC in this 1967 letter to the editor. The "cold" plug and the "hotter" plug confusion may be the culprit of some V6 owners reporting lower gas mileage than they should be getting.