Newb.

[mikefrazer]

I am getting my 1988 Thursday or Friday. It's blue and a 4 speed. The horn don't work and the fan is on a switch and the clutch was making noise. I am looking at swapping in a 5 speed to get close to 50 mpg. This will be my dd. can anyone point in the how to direction for the trans swap

[Team Lightning]

First, Welcome to the site. You might want to add your location under user CP.
Second, to swap from a 4 spd to a 5 spd stock transmission, the 5 spd simply replaces the 4 spd. Nothing to add or modify.

[Bert]

There is a brass sensor, with one wire supplying it, called the thermoswitch found on the engine just left of the thermostat housing. You can test the function of this merely by unplugging it. The fan will then run non-stop! I don't know if you can buy new ones but many Mazda vehicles of similar vintage to yours will have one.

[FestYboy]

i've gotten over 42 mpg with a carb car before, but to get that i had to add almost 10* of timing and the carb was flawless. this was a 4 spd car BTW. i can't say i've ever heard of a carby getting much better than 46. i have a feeling that you'll need to add some aero mods to make up the rest. also, don't expect those numbers or anything close to them unless the engine is running perfectly (including the carb). i also know that mid 40s can be attained with the factory 4 spd trans still in the car, so the trans won't do much unless you run 65+ all the time (the 5th gear drops the rpm about 400 at those speeds). your best milage will come from speeds UNDER 60mph reguardless which trans you use.

[mikefrazer]

The highway I drive on is 60 mph but can get away with 65 I would like t see 50 but really anything better than 35 to 40 would be really great.

[FestYboy]

I'd focus on the condition of the engine and carb FIRST before touching the trans (save for the clutch, which sounds like it's on it's way out). you can break 40mpg in a 4 spd car, but the engine has to be there first.

[neanderpaul]

I bought a carbed 5 speed LX from a lady who claimed 48-49 mpg. It had a bad head gasket. Sold the carb to a guy who claimed to get 48-49 on his carbed 5 speed LX. He bought it because his mpg tanked to low 30's. After he put my carb on his mpg jumped back up to 48-49.

Welcome.

[mikefrazer]

Got it home today. Horn dont work and the fan is on a switch and it needs a pass door handle. Clutch seems ok we will see.