Hi 400E owners,

I wonder what is the rpm on your 400Es when cruising on highway at 120 kmph (75 mph).

Recently I noticed my 400E highway gas mileage deteriorated, it used to get 10 L/100km (23.5 mpg), it now increased to 12-13 L/100km(19 mpg).

This morning when cruising on the highway, I noticed at 120 kmph(75 mph), its rpm was around 2500, I confirmed it was in 4th gear by downshifting it to 3rd.

The rpm seems a little bit high to me, I have 215/60R15 tires which have approximate the same diameter as the stock 195/65R15s(+1%), tires have a circumference 2.02 meters, transmissions 4th gear has a ratio of 1:1, consider the rear differential of 1:2.24. The calculated rpm at 120 kmph(75 mph) is 2217, my actual rpm was 13% higher than that.

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99 BMW 540i 6-speed 110K Km
03 SAAB 9-5 wagon 80K Km
92 400E (Sold) 245K km
Still missing the days with the Benz, it kept me busy.

I guess my 92 400E doesn't have modern lockup torque converter, does it?

If that is true, this may explain that 13% difference.

__________________
99 BMW 540i 6-speed 110K Km
03 SAAB 9-5 wagon 80K Km
92 400E (Sold) 245K km
Still missing the days with the Benz, it kept me busy.