gas mileage question
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gas mileage question
I have a 1980 toyota truck. 4 cylinder five speed. What kind of mileage should i get out of it? Right now it is like 18 to 20, which seems kinda low to me. Right now it has a big fiberglass camper top on it, it this hurting or helping me? Is there anything else i can do for better mileage? Is it better to rev the gear out or shift early and lug it? And finally, the vaccum advance died on the distributor, would i get any better with this working? With gas prices i am trying to get all i can get..
Later chris
Later chris
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From: Wichita, KS
I'd expect mid-20s if you drive it easily. Don't know about the camper on a small truck. On my full-size Dodges I usually got a mile or two better. My '79 F-250, topper or not does not matter. I would not lug the engine at shifting but would not rev it high either. You can feel when it's ready to shift, whatever RPM gives you a smooth steady acceleration. Don't watch the tach--learn it by feel, lots easier for both you and the truck. Yes, I'd replace the vacuum advance.
Post Fiend
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From: Running Springs CA
Vacuum advance can have a huge influence on mileage. It advances the timing at cruise or otherwise under light load. Fix it and you may get 4mpg. One way to get mileage with a stick is to buy a vacuum gauge and try for highest manifold vacuum (lowest manifold pressure in aircraft terms).
Jim
Jim
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From: Drummonds, TN USA
The few bucks you spend on that vacuum dashpot will COMPLETELY change your performance profile!
The effect of having it bad is that your timing is retarded beyond TDC, so you are wasting fuel left and right.
Replace it, then set your timing dead on the money. You will not only save from the timing correction, but less fuel burned more efficiently equals more power. Getting up to speed without your engine fighting itself saves even more...
I've seen this many times. Most people tweak the timing to compensate for it when they go bad, which means their machines after that are totally gutless.
I tell ya what - it will seem like a night and day difference!
The effect of having it bad is that your timing is retarded beyond TDC, so you are wasting fuel left and right.
Replace it, then set your timing dead on the money. You will not only save from the timing correction, but less fuel burned more efficiently equals more power. Getting up to speed without your engine fighting itself saves even more...
I've seen this many times. Most people tweak the timing to compensate for it when they go bad, which means their machines after that are totally gutless.
I tell ya what - it will seem like a night and day difference!
Last edited by Greywolf; Aug 12, 2005 at 06:46 PM.
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Originally Posted by goodwrench
I have a 1980 toyota truck. 4 cylinder five speed. What kind of mileage should i get out of it? Right now it is like 18 to 20, which seems kinda low to me. Right now it has a big fiberglass camper top on it, it this hurting or helping me? Is there anything else i can do for better mileage? Is it better to rev the gear out or shift early and lug it? And finally, the vaccum advance died on the distributor, would i get any better with this working? With gas prices i am trying to get all i can get..
Later chris
Later chris
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Joined: Feb 2003
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I'd say your mileage should be higher. Mid-twentys should be do-able. Now without looking at the truck, let's go over some things. It's 25 years old. Some things are bound to be worn out. Fix what you know is bad. You've mentioned the vacuum advance. That's an excellent place to start. Some other things to check:
Compression, bad rings or leaky valves.
Carb, worn out carb can dump more fuel than needed into the engine
Plugged catalitic converter
Blocked EGR passage
Vacuum leaks or leaky vacuum hoses
Compression, bad rings or leaky valves.
Carb, worn out carb can dump more fuel than needed into the engine
Plugged catalitic converter
Blocked EGR passage
Vacuum leaks or leaky vacuum hoses
New User
Joined: Aug 2003
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From: northwest florida
haygrower
i have two Toyota trucks that are a litle newer,an 86 and 87, both have 5 speeds. They both will get in the upper twenties if you drive them conservatively. Out on the road on trips they get about 30 if you drive the speed limit. I think that Toyota trucks are about as bulletproof as anything on the road!
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