gears & gas

Clutch, transmission, rear axle

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ford71
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gears & gas

Post by ford71 »

I have an f100 with a 360 and a 4 bbl. It has a ford 3 speed manual and a 3.00:1 gear ratio in the rear end. Does anyone know what gears would get me the best fuel economy? I get about 10 mpg now (up to 15 if i'm REAL easy on the accelorator) and was just curious as to what was possible. Also, if I went with 3.73's what could I expect in terms of fuel economy and top speed?
steveheer
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Post by steveheer »

Worse :lol:

Generally the taller the gear meaning numerically the smallest the better the economy. Tire diameter has a lot to do with it too. 3 to 1 in a truck is very tall but it can lumber along at freeway speeds without working--or turning many RPM's. You would probably like the acceleration of the 3.73's--but not the economy.

I would think 15 mpg even with taking it easy is darn good!

JMO
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Leadfoot
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re: gears & gas

Post by Leadfoot »

It all depends on the type of driving you do. go and stop city driving around 3.50:1 works best. but if you do lots of highway driving 3.23:1 or less is best. with a auto trans/ 3spd stick.

Now with that said if you are worried about fuel economy, my shop is just starting to get in to T-5 conv. for all cars and P/U. almost every engine & configuration will be available shortly.
on a rebuilt stocker T-5 can handle about 325 feet of torque, and are performance/race model rebuilt T-5 can take over 500 feet of torque, although its costly to begin with it will save money down the road.
you could build your self a T5 conversion including trans for around 1500 or less including clutch & everything.
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Badgt04
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Post by Badgt04 »

You are going to get the best gas mileage just leaving it as it is!

I think my FE is getting about 6mpg hahaha
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ford71
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re: gears & gas

Post by ford71 »

I'm not too worried about milage, I just wondered what lower gears would do and if any one particular lower ratio would be best on fuel. I think I'm going to go with 3.73's. Thanks


My truck got 6-7 mpg before I switched over to an edelbrock 600 cfm 4 bbl, I could'nt be happier with that modification. All the added power and increased gas mileage. now I generally get 10; but like i said earlier, up to 15 if a take it easy( NO burnouts or fast acceleration and if I keep it i 3rd most of the time.)
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