Second day with my Prius C

The Prius C is a great little car - but it is a gas car at heart and my experience is that it's frustrating to try to keep it in EV mode. To the point that I'm hoping to replace it with a pure electric car later this year. Don't forget that every electron you consume was generated by the gas engine in the first place, so you're really only getting a benefit if you're consuming those electrons during driving conditions where gas engine propulsion would have been less efficient.

If you're as CDO about saving gas as I am then a way to shorten the warm-up time is to install a block heater to pre-warm the engine and perhaps even use a cabin heater to pre-warm the cabin. The car will still need to run the engine to warm up, but it won't run for quite as long and it sure is nice getting into the car when the cabin is already at a decent temperature. The downside is that you have to remember to go out and plug everything in before you plan to leave.

If you calculate your actual fuel economy by noting how far you've driven between fillups and noting how much gas went into the tank you'll probably find that the number shown on the driver information screen is about 5 to 8 percent optimistic.

 

I agree with Sean. "If you calculate your actual fuel economy by noting how far you've driven between fillups and noting how much gas went into the tank you'll probably find that the number shown on the driver information screen is about 5 to 8 percent optimistic." I am averaging 57mpg actual, but the dash shows 61mpg (7% difference). This is with using winter gas.

 

Using an engine block heater just means that you are using electrical energy to heat the engine rather than gasoline. But, much of the engine heat from the gas comes for free as heating the engine is a side effect of propelling the car. So, while heating your engine may help gas mileage, it is probably increasing your overall energy consumption and may end up costing you more.

 

I'm less concerned about cost and more concerned about using less gas. And since all the power where I live is generated from hydroelectric dams it's greener than warming the engine and the cabin with fossil fuels - especially since I spend a fair bit of time sitting at stop lights where the engine doesn't have to be running for propulsion.

 

I don't think I would want to worry much about using the engine block heater in moderate winter climate. It seems to be an overkill; the car occupant would need heat during the trip and, that seems to be more efficient coming from the gas engine. This is more true if your trip right after the cold start is a long one, in which you have plenty of opportunities to make the driving efficient; the "wasted" gas to warm up the engine would be even out with your driving style during that long trip. Just my 2 cent

 

If cold weather requires a longer engine warmup, then a longer trip means a lower miles per gallon, but that extra warmup time still uses more gas. Say, for example, that it uses an extra 0.1 litres - no matter how far you drive it won't negate the fact that that extra fuel was used.

I sometimes use a block heater and a cabin warmer here in Vancouver BC where temperatures are close to freezing. I've done some very rough estimation of how much savings I get based on the fuel economy display and I figure it's around 0.1 litres or so per outing. Where I live the cost of that gas is very roughly around the same cost as the electricity I pay for to heat the engine and the cabin. So I'm not really ahead or behind by anything significant, but I do feel better about not wasting that gas (which adds up over the month) and I like starting my drive with a cozy warm cabin without having to run the engine excessively to heat it up.