I started up my Gen 3 this morning with outside temperature reading -3C and it took almost 15 minutes of ICE idling to warm up. As we move towards improving thermal efficiency, the heat generated is also reduced and also the capacity of the engine to heat the car. Back then, when I was looking through the various brochures for Prius Gen 3, this was one thing I noted that the Prius Gen3 was supposed to have an "enhanced" heating system consisting of the engine itself and the exhaust system helping the car heat up quicker. What I didn't realise then however was that we were talking relative terms here, the Prius ICE was more thermally efficient so when they said it heats up quicker, the comparison was being made to itself (possibly Gen 2). After living with a Gen 3 for nearly 4 years, I can quite comfortably state that the Prius does not heat up as well as a normal car and this is especially noticeable in the winter. Furthermore, we all know that the ICE comes on when we increase the internal temp and it remains on till desired temperature is reached. It is actually very inefficient to keep the whole engine running just to heat up the car so this got me thinking... Why can't Toyota come up with a simple Heat Generator that sips fuel off the main gas tank. The sole purpose of this generator would be to heat up the car as efficiently as possible and this would negate the need to keep the ICE running. Of course there will be technical challenges to implementing this but from a layman's perspective, I cannot see any downsides. Any thoughts from my fellow members?
Can you specify where you mean getting the engine up to operating temp, and where you mean making the cabin comfortable? I think Toyota always means the former, but that you often mean the latter. But I am guessing.
Yes, I am talking about making the cabin comfortable. And I don't think the Prius brochures were referring to the engine as it would be irrelevant to the ordinary consumer. If that were the case, it would be similar to (let's say) saying the brake system pressure has been enhanced - technically would make sense but no point having it in a cosumer car brochure.
The heat is weak in the gen 3. It takes a long time to get going. Anyone remember the old vw bug heaters. I guess it is an unfortunate side effect of wasting less fuel. I would bet the next generation hybrids will have better heat. I use the heated seats in my 2010 prius frequently. I wonder if a block heater would help the situation.
Make sure you have the air on the Recirculate mode and A/C turned on (to prevent fogging up). If you are in Auto, it will turn on the A/C. I love the heated seats. The heat transfers super fast through "skin" contact, rather than through air.
Our morning lows have been in the low teens for some time, but I have not seen the heat issues mentioned above. I do not yet have any grill blocking in, but I have decent heat output within 3-4 minutes. I have found the Prius to be better than a lot of large-engine cars in this respect. Idling is probably not the best way to warm up the engine is you are looking for cabin heat. Putting a load on the engine will substantially speed up the process.
It's winter here in ND. We have already had some below 0F days. For A few days I just started and after a few seconds drove off cold. Our two miles of Gravel road leading to our farm has a fresh coating of very coarse gravel. Driving off cold in this rough stuff is miserable, I get no usefull heat for the first 2 miles and the cold interior panels squeak and rattle when the interior is that cold. I decided it is worth it to start my Prius and walk back to the warm house for 10 minutes. When I return, the ICE is warm and shut down, the traction battery is warm and the interior is toasty warm. The car them drives off easily and the interior squeaks / rattles are gone, as the panels have expanded and softened in the heat. I am 65 years old and retired, at this point I chose not to beat the car and myself over the cup of gas it takes to warm it up. Life is good
The Prius is not made to be the most fuel efficient car, it is made to be the cleanest in terms of emissions. That means the engine needs to heat up to S4. It could turn it off early, but the pollutants out the back would be higher. If you are constantly doing short trips where the warmup cycle cannot complete, then you need the PiP. Now the cabin will not heat up until the engine is getting warm. That way it doesn't blow cold air onto you and doesn't cool the engine even more. If you want heat, turn the defrost on full MAX HI temperature. That will start blowing hot air much quicker if your Prius is in a region that included the electric heater element.
Hmm I wonder whether this is what I was missing. I was not aware of this "electric heater element" feature that comes on when cabin temp set to HI. I need to try this on a cold morning and see.
Can I respectfully disagree with you on this ? The past few cars I have had - all medium sized family cars, have been noticeably better at cabin warm-up. I generally agree with you on this however, from a practical POV it is not easy to stay inside a frozen car early in the morning pressing the accelerator pedal for the car to get warm.
Actually I think we are diverting away from the point I was making originally... that the engine could not be the most efficient way to heat up the cabin. Of course we need to make use of the heat generated (as a by-product) by the engine to help with cabin warming, no arguments with that. But the point I am making is that it is fundamentally wrong for the ICE to kick in just because cabin temperature is low. A good example will be if you were stuck in traffic or moving slowly on ice, the hybrid battery will be fully charged because the ICE was on to heat up the car, and after a while the cabin will need to be warmed up again and the ICE will come on and it will run way faster than idle speeds during warmup. If there was an alternative (and more efficient) heat generator, the engine can be freed of this duty and allowed to drive the hybrid system optimally. The engine will still (passively) influence the cabin temperature but it will no longer be the active element that maintains it.
If you park in your driveway not street parking a small space heater set inside the car for 10 minutes does a wonderful job warming up everything from the steering wheel to the head rests. Speaking of seat heaters has anyone tried the forced air type seat heaters. The seat is like an air hockey table. Tiny holes covering the seating surface allow hot or cold air to cool or heat the front seats. This type of heater feels different than the heating element type that is found in the prius. I think the fan forced air seat climate is the ultimate. I wonder if Lexus ct200 front seats would fit in a prius. I believe the ct has fan forced seat heaters, since it is a toyota product the bolt pattern might match up. I guess the air bag situation could be tricky.
Have you blocked your lower grill as has been suggested yet? Do you not have heated seats? Might be wise to put on some warm clothing.
Remember heat is the byproduct of inefficiency. The best cabin heat is going to come from a giant crappy engine like a V8 monster in a US-domestic car. The cabin will warm right up, but then it will continue to guzzle petrol, still producing boatloads of heat even when you don't want it. An old 1968 Chevy I was helping to work on heated up the best. In fact it heated up so well, that if it was just idling there, the entire engine would heat up to where the radiator fan kicked into full speed within the first minute from a cold start. If it remained idling without air movement for a couple of minutes it would overheat.
It also depends on your driving condition. If you merge onto highway right away, you'll get cabin heat quickly. If you only drive in slow city streets, it'll take awhile to warm up the engine (and the cabin). For the 2nd scenario, you can improve it by blocking the grill and more importantly, recirculate the air so that no new (cold) outside air is drawn in.
I second the motion of putting the air on recirculate with A/C on to prevent fog up. Recirculate re-warms the already warmer inside air and the A/C has very little power draw at low temps. The A/C uses about 150 watts for about 10 seconds out of every minute so little impact there. Also the current draw will not be primarily from the battery but the more efficient generation path from the MG1 and MG2 during the warmup. If it's in the low 40s and sunny, you can put the temp setting to HI and with outside air setting (not recirculate) and the fan switch to off. With this setup, some of the air due to the car moving blows through the heater core (no cold air mixing), without the Prius computer switching on the engine for heat. Although what I do, is turn off the heat while coasting, gliding or decelerating and switch on the heat when accelerating or maintaining speed until the coolant reaches about 140 F and I can achieve 50+ mpg on sub-freezing days for my 22 mile commute with lots of stop and go. Commute average speed is 22 mph for my 1 hour commute. This significantly improves my mpg for the first 3 or 4 miles which can have a big impact on your overall mpg, understanding that going from 15 mpg to 20 mpg saves more fuel than going from 30 mpg to 50 mpg. If on a real cold day you can get that first 3 miles mpg figure up from the teens into the 20s, it is likely you can significantly improve your winter mileage. In my commute getting 50 mpg in winter instead of 45 mpg saves me 14 cents each way, so don't worry too much if you lose a few mpg. A 10 mpg drop in winter on a 50 mpg car (Prius) costs you 38.4 cents on a 22 mile drive, a 10 mpg drop in winter on a normally 30 mpg car will cost you $1.28 on a 22 mile drive. This assumes gas at $3.50/gallon. Most of the 90 cent difference (Prius vs std car) is the gas used producing heat. Now if Toyota could set the A/C to run in reverse as a heat pump to lower engine on time, it's possibly easily doable, but icing on the front "condenser" core and lower effectiveness during very cold weather might be reasons why this wasn't adopted.
Just to summarize, some things doable: 1. Grill Block (plumbing pipe foam insulation tubes commonly used) 2. Block Heater (available from Toyota). 3. Electric space heater in the cabin.(aftermarket heater) I do 1 and 2, 3 is useful especially if you park outside, get frosted windshield.
A warm coat and blanket for the legs with the heat off for the first 10 minutes is another quick and dirty solution.
