Prius electric mode - Prius EVMODE - Toyota Prius Electric Only Mode Kit how many of you guys have this mod done? how effective/safe is it? doesn't the factory toyota keep it in EV (no gas engine) mode as long as it doens't go over 33 mph anyway? and in reality, how much MPG does it help? before and after? this just differs from the plug in electric mode because you can drive less distance and slower? thanks for any and all help
It works It won't help your MPG It works just as the OEM EV button does, certain conditions will kick you out of EV or won't let you enter. It will stay in EV until you pass 34mph. You can do a more effective (ie. instant instead of waiting 3 seconds for activation) EV mod for a couple of dollars (switch and wires). http://www.google.com/url?sa=t&rct=...L45J8B&usg=AFQjCNGrWalk7CGBQSIWd8hnzNzavlHMFQ
+1 on what Evan says. The EV mode switch can help get very modest FE gains… but the slightest misuse is a MPG killer. I installed one ~3 years ago when there was hot and heavy debate about its usefulness in getting better MPGs. I couldn't get a sense of the issues involved, so I jumped right in. Forget using it for extended EV. Every bit of energy you draw from the HV battery to drive in EV has to be put back with multiple conversion losses. IMHO, its best use is to surpress the ICE coming online. Anytime the ICE is turning over and you aren't moving is a complete waste of gas. At this time of year, when warmup time is lengthen due the cold air temps, the non-EV switch can be useful. First off, after an overnight cold soak at 30 degF, you can't access the EV mode because the HV battery is too cold and sluggish in both providing and accepting power. The HSD uses repeated small charges and discharges to warm the battery. As part of this strategy the HSD tries to keep SOC up around 65% as opposed to 60% when the weather is warm. Whether or not the HSD will allow EV use, when ICE coolant temps are below ~110 degF, the ICE runs all the time whether you are moving or at a stop. The HSD is warming up the ICE and cat-converter to minimize pollution, actually the primary reason for the whole Prius-HSD-hybrid concept. Between ~110 degF and ~145 degF the ICE will shut off at stops if the heater is off and you push very firmly on the brake pedal. (Sometimes in this coolant temp range you have to pump the brake pedal very firmly twice to get ICE OFF.) But, it will come back on randomly. Here, finally, is where the non-EV switch is useful. By going into EV when the car is at a stop, ICE ON is surpressed. But, here too is where you can screw it all up. You must switch out of EV mode, using either the switch or a quick jab at the accelerator/go- pedal. If it's a long light, its too easy to forget you're in EV mode and draw heavily on the HV battery as you accelerate away... all the little gains are lost. Above ~145 degF the HSD tends to not run the ICE when the car is stopped. Once coolant temps are above ~145 degF you can usually get through a short stop without using the non-EV switch. But beware. If for whatever reasons, long glides, long stops, extremely cold temps the coolant temps fall to 145 degF, the ICE will come on to keep the coolant temps up. There you have it. I doubt that in the past three years I've recovered the initial expense... but I'm working on it every cold day. :rockon:
