After Toyota installed an Engine Block Heater in my Plu-in, I have gotten much improved mpg numbers. In fact the mpg on shorter trips to town and work (some 3 to 5 km) is halved This is when the weather is cold and I need to have heat in the coupe. The first week after the intallation the mpg was 117 mpg. After some longer trips the next weeks saw 78 mpg. As spring approaches, I look forward to driving the car in pure EV mode as much as possible. That means all my commuting and trips with the kids to activities and such
I've never seen such happiness at having one's fuel economy halved! ;-) I'm guessing you mean it's doubled...? Anyway, I came up with a jury-rigged battery-powered heater that lets you have a little heat without running the engine. It would work especially well for trips as short as the ones you mention. If you're interested, look for the 'Heater In A Box' topic.
No - you can also self-install the Toyota block heaters. I did mine and like it. Many EBH installation threads here. The engine has a cast tunnel sleeve for the EBH on its backside, by the cabin firewall.
OP is in Europe, where they measure economy in L/100km, the inverse of how we do it, so actually halved is what he would witness. The strange part is he said "mpg"... and then listed distances in km... ;-)
Not a dumb question. As a pretty safe engineering guess, I would say the engine block (which affects the coolant temperature) needs to be warmed in order to increase fuel economy and provide cabin heat (via the coolant).
Wait. The pictures I've seen of the EBHs all have power cords with what look like normal 120v plugs, which I assumed needed to be plugged into wall power. Is there a way they simply run directly off of the car's electrical system and then automatically shut off after the engine block has reached operating temp?
Block-heaters are standard equipment on all cars here in Canada. I see it as a trade-off between paying for several hours of electricity consumption by the block-heater versus 3-4 minutes of running the engine to warm it up. Since my Prius came with 0-W20 grade synthetic engine oil, cold starts are not much of an issue, and I rarely see the need to plug in the block heater.
The block heater is 400 watt, and a couple of hours is sufficient use, get's the temp near the point that it stalls, doesn't climb any more.
It maybe on the prairies, sadly not in coastal regions. I really think it should be a factory install, guess it would take legislation. The part is pretty cheap, it's the install cost that hurts. With the Prius at least no coolant is drained, but other manufacturers, Honda in particular, immerse the heater in coolant, and the coolant is drained/replaced (ridiculously early) when the dealership does the install.
There are a few problems with that idea: The Toyota block heater uses 400 watts of electricity for at least an hour to achieve much effect. To drain that much electricity from the car battery is far less efficient than running the engine for a few minutes to warm it up. The Prius GenIII uses a heat-recovery system built into the exhaust system, which I find will warm up the engine in 3-4 minutes in cold weather. Secondly, the battery voltage is wrong to run the block heater. An idea which has been brought up here before is to interconnect the interior heater with the charging cable. Perhaps a block heater could be incorporated into that as well.
I stand corrected; dealers here have always added the block-heater option by default, but I can understand the reason for not having it installed in the Lower Mainland, where the price of it is a small competitive price advantage (and a great money-making opportunity for installing it). Personally, I rarely use block heaters, because I find that the winter-grade synthetic engine oils make it unnecessary.
A block heater never get the engine to operating temperature, that's not it's intent. It raises temps about 30 degrees centigrade. And yeah, no way the car's batteries could handle this, and it's sawing off the branch you're sitting on.