Date registered: Feb 2009
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Highway RPM's high?
I was slightly curious about the lower gas mileage of the AMG offerings, so I set out to compare the rpm's at cursing speed to my current car. Granted, the AMG's cars are not bought for their great fuel economy, but hear me out:
At 75 mph, my Firehawk's engine rpm's are at 1,680 in 6th gear. I've calculated that the CLS63 would be running at 1,895 rpm's at the same 75 mph in 7th gear (can anyone confirm?). At 60 mph, the Firehawk engine spins at 1,344 while the CLS63 engine spins at 1516. That's 12.8% more revolutions per minute than my Firehawk!
If my 5.7L V8 engine has the torque to handle highway speeds at the lower rpm (sure, I've passed people in 6th gear), I would think so would the standard 5.4L V8 and AMG's 6.2L V8 (the torque chart on AMG's website for the 6.2L starts at 2,000 rpm for the 6.2L, so who knows?)
Why does Mercedes spin these V8 engines at the speed they do? Can they go lower?