Gas M.P.G. up +5 from last tank

Well last post on this subject a few weeks ago I was getting a sad 14.5 miles per gal. only 175 miles on FULL TANK I had old spark plugs and some very old wire set. I put some new plugs ( NGK BP6ES ) as told by fellow members and put a new bosh spark pulg wire set and the miles per gal. went up to 19.5. ( 230) on a tank this time. Nice but I would like a little better.

Only city driving . For those who have old plugs ya might want to change them soon !

Now Jimmy Hilton could probally get me up to 23 or 25 if the carbs could be tuned up a bit correct?? Most of you guys were getting about 20-25 city

I have found that one-tank readings are totally inaccurate.

the fill point is usually 1/2-1 gallon different even with the same pump.

I'm fighting a problem with my SAAB which gets about 22 but I think should be higher. I have gotten as much as 28 in short runs (100 miles, refill, check) but I believe the difference is my error not a real thing.

The B...well, i think I'm in the 25+ range but the speedo isn't working because I have not installed a proper sensor (electronic speedo).

At this point, it depends a whole lot on how you drive it. In my blue '79, I can get 24/34 (w/od on Hwy @ 75-80ish), but I can also get 15 around town if I am having too much fun.

When I first got my '73 GT it got 12-13. After a good tune up and one of Jeff's rebuilds I'm getting 17-18. My '74 roadster gets 22-30. I sure would like to get my GT up in that neighborhood.

Hi Paul,

It will be an interesting test to see about the before, and after. I don't think I know if the carbs on the way, are for your roadster or GT.

Hey Jimmy - The HIFs you rebuilt for me are for the '74 roadster. It will be a good test just the same to see if I can do even better. I pulled the tappet covers today and cleaned 30 years of gunk off the side of the engine. I'm going to call jet-hot on Monday and talk about getting the ex manifold coated. I figured those carbs are going to make the rest of the engine look pretty ratty.

Looks like the UPS man comes with the carbs on Thursday!!

The GT is more of my problem child - just has a few bugs to work out.

Check for vacuum leaks. Depending on altitude, you should get something above 15" -18" Hg on a vacuum gauge on a four banger. If you are up in altitude the figure can be towards the lower one. Also, you can get lower vacuum if the mixture or timing is off. You don't necessarily need the highest vacuum attainable, but you do want it to be near there and in the "Normal" range.

Check valve clearances. They will affect gas mileage as well.

If you have one of Jeff's dizzies, and it is set up as he recommends, timing should not be a problem.

Make sure the carb(s) breathe freely. A new air filter(s) can help.

Coolant temp can adversely affect gas mileage, but even that is relatively small factor.