Quick gear Ratio/rim size Questions...

[emmahumpfritter]

I'm searching around the site tonight and discovered the drive ratio difference in the early/later 4wd's. My question is this: Which tercel has the lower RPM's at cruising speed? I'm interested in max-MPG's on the freeway.

Also, search brought up loads of rim info, since many of the threads are older, I'm wondering if the group has collectively settled on an ideal 14 inch steel wheel upgrade with stock running gear (no rotor/brake swaps, etc.)


Thanks,
Brenton

[takza]

The lower the final drive ratio...the lower the rpms....'83-'84. IMO...the cheapest route to 14" wheels are the steel Escort wheels....or any other good bargain on 14" steel wheels.

As far as RPMs vs mpg...it is possible that you can have the rpms too low at cruise...causing a need to run too deep into the throttle for max mpg. I think a vacuum gauge would probably indicate what the best LOAD would be at cruise. Might be some kind of calculator online that would tell you?

I haven't seen a need for brake upgrades...I use Advance gold pads. Seemed to do OK in the mountains carrying 600 lbs...but I use engine braking.

[Petros]

The early 3.73:1 ratio will have lower cruising engine rpm, and taller tires will too. Oddly there does not seem to be a noticeable difference in MPG with either diff ratio, the only advantage I think is the slower the engine speed there is a bit less engine noise at hwy speeds.

the lower number final drive ratio and the taller tires will have the effect of making the car more sluggish from a stop. Using EL would help, especially when starting on a steep hill, but that means slamming it into 4wd (which I have had to do in steep down town traffic), I just pop it back out once up to speed, or before I have to make a turn on pavement.