Cruising RPM?
 

I recently bought an '89 Supra, very nice little ride but I have no history on it at all. I have the automatic overdrive transmission, non turbo engine. At 70 mph the tach is showing about 2850 rpm. That seems rather high to me. From a dead stop the transmission shifts four times and is solid. Fuel mileage is normal in the 20 to 24 range. The VIN shows 372 for the rear axle. I'm curious as to what is considered normal RPMs a 70 for a similar Supra. My guess is someone changed out the rear end to get more low end but as I said, I have no history to work with. Thanks

You posted this in the wrong section. I've moved it to the MKIII forum.



No, that's about right. The N/A's all came with a 4.30:1 end gear where the GTE models came with a 3.91 or a 3.73 (pre89 models and 89+ models, repectively). The 3.91 end gear cruises at about 2720 at 70MPH.

If you want better mileage you may swap in a taller end gear from a GTE model but your speedometer and odometer will be off. The speedo driven gear from the corresponding A340E should fit though and correct the offset. (W58 and R154 gears are not interchangeable though) You will lose some acceleration but it's not a huge difference when just swapping to a 3.91... the 3.73 makes a much bigger difference. If you do not have LSD you'll need to swap the entire differential.

Thanks for the info, I did manage to track it all down on line. This is a 4:30 rear end. Dang fun and doing 23 mpg highway so pretty pleased.