I'm not sure you could switch the ICE off & on, and do much better than the car's computer already does.
This 20 mile round trip was done in a
very heavy traffic area, with hills.
You will notice that 62% (12.3 miles) of the trip was done in EV mode.
When the SOC is good, the car will stay in EV mode up to 45 MPH,
until the pack gets low or the hill gets steep etc.
The ICE only comes on when needed. It's so seamless, you can't tell
if it's running or not. You have to look at the power flow display.
I was surprised to see it run for 10 or 15 seconds and turn off.
It's amazing how fast the pack can recharge down hills or by ICE.
During that trip, the ICE may have been on & off 50+ times..
The EV range is short. Only about 1.25 miles.
But a slight downhill EV run can be much longer.
If you just want to move your car around a parking lot, without the ICE,
you just press the EV button when you turn the key to 'start'.
(Which turns on a 'Ready' display). If the SOC is ok, the ICE stays off.
Because of the way the battery is protected from getting a very low SOC,
it will last for many years. The car's computer program changes
the modes of operation very effectively.
The only EV hack I can think of is replacing the pack with a higher AH pack.
But, it's likely the control program would need to tweaked too.
I can't see that you would gain much, unless it was a plug-in.
My first hack idea was to add another 144v pack in parallel..
It might increase the EV range a bit.. Hard to say.
The rest of the system might be totally optimized to run with the pack..
BUT if it was charged from the grid. Maybe..
The plug-in idea might work if when you were coming home, you slowed
down under 45 for the last mile and hit the EV mode button..
When you got home, the pack would be in a lower SOC,
so a charge could be accepted via plug-in.
(Otherwise, the ICE will be doing all the charging).
Making the car lighter might increase it's EV range a bit. Take out the spare tire, tools & etc.?.
Some Prius Chat guys tow boats etc. But Toyota says not to tow at all.
Prius c Main Forum - PriusChat Forums
It will be hard to get warranty work done if you have been towing.
http://shop.tlcentral.com/store/pc/v...idproduct=1060
Not sure about the high speed MPG, but I read about one guy in Florida
who was running around at 85 MPH and complaining about 35 MPG.
You might be able to find out here:
Prius c Fuel Economy - PriusChat Forums
The 'c' is the top dog of MPGs today. Only the EVs can beat it. (short range).
If you get a 'c', the most effective way to get the best MPGs is to learn to hypermile.