Originally Posted by WaltPA
I wonder for how long (time wise, miles wise), this prototype Cayenne can cruise at 70 mph
on batteries alone?
That's another contention I had with this news release. Sure it can run on 70mph but how long. I believe one can answer that question using some math and comparison to current hybrid performance.
Lets first use a simple scenario for starters. The cayenne engine runs at 20 mpg on highway (presumably 70 mph
). If it can run 50% of the time on engine and the other half of the time on EV only. That means for the amount of gas that he would typically run in a set distance in a conventional cayenne, it would only need half that amount for a hybrid. That is an increase from 20mpg to 40 mpg, aka a 100% increase in fuel efficiency.
But...the stated FE is only 25% improvement. Based on this, the hybrid cayenne would on average be running only 1/5 of the time on EV mode. For a 50 min cruise at 70 mph
, it can be in EV mode for 10 min of that time. That is pretty good but is that realistic? First off, 10 min at 70 mph
means that the cayenne can cover 11 miles on EV. That is a little hard to believe considering a camry with ~40% FE, can barely sustain 11 mile at 40 mph
on the flat road. Second, the cited FE is likely a combined highway and city. FE will be lower for a long duration highway driving.
So how long do I think it can run on EV at 70 mph
, 2 mins tops (and that's me being very generous and kind this morning.)
...and that's my $.02