It is getting to the point here in S. Jersey where the mornings are getting colder and frosty and I'm wondering what the best procedure is for warming up the engine either before or during starting out. Should I start it and give it a few minutes and will that warm it up or just waste fuel. Or should I get in and immediately hit the road in a gentle way. I don't normally use a freeway to work but mostly country roads that are relatively flat. Trying to develop a system that will be economical but also good for the engine(s) and battery. Here, the temps. during the cold months avg. 20°F - 30°F with some teens mixed in and occasionally 5° - 10° during the Jan.-Feb. period.
some say, (unlike regular car) let it idle in the driveway until it shuts down, then drive off normally. i have a hard time with that and just start it and drive gently for a while and pick up speed after a few minutes. but i'm in a garage which moderates the temp a bit.
Not diggin' the winter MPGs... Still enough to make any other auto driver envious but it's getting harder and harder to keep them up where they were.
Lots of tips in the Fuel Economy forum. Make sure tire pressures are nominal (pressures drop as temps drop), lower radiator block, but in general temperatures dropping means MPG will also go down. I'm using my block heater to preheat for a few hours (with a timer) before I head out in the morning, and it does make a difference as to how fast the engine warms up & I get heat inside the car. Snow tires (Blizzaks) have meant about a 15% drop on my mileage (arrg), but I feel more secure on the roads.
Thanks for the replies guys. Keep them coming. Ah, another Phillies Phan. When do pitchers and catchers report????? The Eagles are making me crazy.
Since you're not jumping immediately on a highway I'd second the 'just start it up and drive away' answer. You might investigate some of the threads on grill blocking to try and minimize the engine running just to keep the coolant temperature up, or possibly install an engine block heater - 3 hours or so plugged in will bring a cold engine up to the point where it would shut off when standing still (103 deg F). Also if you're stopped at a light the engine might keep idling if you have the heat on - turning the heat off while stopped will allow the engine to shut down and not waste that gas. Unfortunately it's a fact that you will get lower mileage in the winter. It's still better than 95% of the other cars on the road, however.
I have three city blocks to drive before I get to a 45 mph thoroughfare. By the time I drive 25 mph through my residential neighborhood and get to the thoroughfare, my car is above the 105-110 degree F warmup threshold. So, by the time I have to accelerate briskly to get on the thoroughfare the car has warmed up sufficiently. So, I jump in and drive on cold mornings. I also lower my Climate Control temp setpoint during this warmup time and do not turn it up until the coolant temp is up to temp and ready to blow warm air. This will help keep the engine from running to heat the cabin if I have to stop before the engine is warm.
It gets colder than you think, but just not as long as it does in NJ Last winter we had a few weeks of 20 degree weather and a few days in the teens !
Use an engine block heater. The engine warms up faster and you get heat faster. Just start and drive. If you drive gently, the car will use battery power anyway (even if the engine is idling). The engine won't power the wheels unless you stomp on the pedal or it warms up (I think to S2 at least).
So Tideland, does the exhaust heat recovery system work better than the older thermos system? How bad can the mileage drop? Well, summertime I average 4.5 l/100 km if I'm careful, in the city, short trips mostly. Today I'm seeing 7.0 l/100 km on the MFD (it's usually quite close to reality in Pearl). I've been bad on this tank, letting the engine run while stopped at lights. Hey, it's cool right now and I'm getting lazy (-15C tonight, just above 0F). I start and drive gently (garage parked, insulated but unheated garage). If you let it idle, it takes a LONG time to warm up a Prius. At least a GII.
Ohhhh yesssss it does. It makes a HUGE difference. I mean, look at my sig. The lifetime average of the 2010 is better than the 2005 despite being in a much colder climate and with fewer fill-ups. The worst tank that I saw 5.4L/100km MFD, 6.11L/100km calculated at -40°C. (Yeah our 2005's MFD readout is much closer to reality than my 2010 as you can see above as the worst-case scenario for discrepancies). My commute is 9km, no highway so it's hard to get good mileage so I'm fairly happy with my mileage given my short commute and short trips. Right now, it's reading 4.6L/100km (so closer to 5.0L/100km) and it's fairly new into the tank (9 bars left). I idled for at least 2 minutes this evening trying to make a left, longest I've idled this winter cause I didn't plug it in at work. In the 3G, the warm up is much faster. I would say 10 mins to get nice and warm around -10°C. At 0°C, the 2G won't shut off the engine until you've done at least 10km and you've come to a complete stop. With the 3G, it will shut off on the fly (change in programming) so you don't have to come to a complete stop at least once and in ECO mode, it shuts off after 5km (longer in normal but I rarely run in normal mode in the winter to minimise wheel spin and of course encourage engine shut off).
I get in my car and drive. I don't use the heater/defroster unless I am going downhill or uphill, I don't use it at stoplights. I also block my lower grill and would appreciate advice on blocking the small upper grills. Good luck,
If I were you, I let it do an initial warming up during the first 50 seconds of S1a in P position, then start driving. Ken@Japan
What's the difference between idling for 50 seconds and rolling slowly down the road (where safe to do so such as a residential street)??
