Quote:
Originally Posted by Flying Ace
Quote:
Originally Posted by BimmerMat135
There is no way a Phev will beat a diesel on the highway. Actually the X5 40e is worst than the 35i on the highway. A gas engine need more fuel to produce the same power it's that simple.
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You're not considering regenerative braking and the fact the battery will still partially power the vehicle at high speeds. The battery isn't completely unused on the highway.
Porsche Cayenne SEH owners are reporting over 30 MPGs of gasoline use on the highway. The Cayenne diesel returns 28 |
Well i did consider that. For the regenative braking if your going downhill probably you will end up going uphill at some point so you don't really "Â*gainÂ*" energy. So let's imagine a scenario at a constant speed on the highway 70mph. If you want to have diesel like fuel economy you will need to compensate for the 25% disadvantage. So at 70mph you should need around 20kwh to maintain your speed in the X5 diesel and about 21kwh in the X5 40e(considering the heavier weight). So to keep fuel consumption at diesel level your ice will use 15kwh and you will use 6kwh from the battery. After 100 miles the battery(9.2kwh) will be dead. So therefore the ice will have to provide 21kwh and then your fuel consumption will be around 25-30% higher than the diesel X5. So for short trip on the highway maybe you can get diesel numbers but any long trip forget it.