EV Mod

Sounds ideal for EV. I don't have that much downhill run, but in traffic jams I use ev sometimes just as you plan.

You don't say where you are but keep in mind you won't get EV starting out on the downhill when it is either too hot or too cold. My EV works at 40 deg F usually but below 32 it won't.

In summer EV won't work if car has been parked in the sun till the battery cools.

 

I advise against using EV to accelerate from a stop. It is not efficient. Briefly (as I've stated elsewhere) the engine is inefficient at low loads, but the electrical system is inefficient at high loads (since it must be rechaged from the battery - unlike an electric car, which is recharged from the grid).

Accelerate using the engine, then use the EV to maintain slow steady speed. Once the car is fully warmed up, you can generally accomplish this without the EV switch by "feathering" the pedal: letting off it completely for a slow count of 2, then touching it ever so gently to maintain speed.

However, in the kind of slow-and-go/stop-and-go traffic conditions you are describing, the car often does not react fast enough to the changing traffic speed, and the EV switch can be very nice. But I would allow the engine to do the accelerating, unless it really is stop-and-creep driving.

In any case, although the car will put itself in electric mode up to 42 mph, the EV mode initiated by the switch is limited to 34 mph. And, although you can accelerate harder in EV mode than when the car itself goes electric, there is still a very low acceleration threashhold before the car goes out of EV mode. It requires a very light foot to use.

I think you will benefit from the switch.

Take a look at the Knowledge Base. Evan has an article with instructions for installing a switch for next to nothing, using any old cheap momentary-on switch. I use the Costal switch, because Evan's DIY method requires more dashboard dis-assembly than I was willing to do, and $45 is cheap for me. But if you are handy, and your budget is low, you can do it yourself for practically nothing.

Costal Dave's version has the advantage that the c/c stalk is right at your finger; but the disadvantage that you have to hold it for about 3 seconds for it to trigger. (Less time, and it's the c/c-cancel function.)

 

I regularly accelerate in electric mode usually without needing the EV button, and I get pretty good mpg except in winter. My record tank so far was 59.

There's no reason to start the engine needlessly. If you really need power where the engine is more efficient it starts without your help.

The advice to not use EV for acceleration is sometimes valid, but it depends on other things too. It does relate to engine loading and lots of other things like whether you have extra charge on the batteries to use up.

Clearly if you can start out on EV and coast for 10 miles and then run engine for 10 mile on the freeway, you are saving gas.

If you accelerate in EV and then stop at a traffic light where the engine won't stop because it is recharging the battery you lose.

If your choice is EV acceleration or EV at constant speed for longer time, then using engine to accelerate makes sense.

You need to make your own tradeoffs and not consider the EV acceleration part in a vacuum ignoring where the battery gets its charge back.

 

Valid points.