Quote:
Originally Posted by mkuper
joeH the calculator and info in the trutrack was helpful. I am more concerned with gear ratio selection. Currently with the 3.55 gears @ 70 MPH the engine runs about 1800 RPM. I don't think the converter is even locking up and I cant use overdrive unless I am driving on a perfectly flat road with nonexistent headwind. From the aforementioned calculator @70MPH 4.10=2046 RPM, 4.30=2145 RPM, 4.56=2275.
Which one would be the best choice?
Mike
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In my opinion using RPMs alone to determine best gearing is not very effective. There's a lot more to it than matching someone else's engine speed.
Beyond that I'd say you have to define what "best" means to you. Best fuel economy isn't achieved with same gear that prevents frequent downshifts out of OD, or offers best acceleration, etc... What do you want to accomplish?
If you know what MPGs you get at 70 MPH, you can then do a little reverse engineering to find out how hard your engine is working while cruising at 70 MPH. If you have a scan gauge even better. From that you can then choose a good overall compromise based on your personal objectives (i.e. -- fuel economy vs acceleration, etc..).
Personally, I'd go with the lowest gears that won't make a huge difference in fuel economy.