Warming Up: P&G? PEOG? Steady Throttle?
 

So pulling out of the driveway on these cold mornings got me thinking...

"What driving style is best for FE in the cold? P&G? P&EOG (Pulse & Engine-Off Glide)? Steady Throttle?"

I drive a Honda Civic and it seems that it takes longer to get to Operating Temperature than other cars. My Wife's Jeep and friend's Lexus takes much quicker to get to operating temp.

So while running rich on these cold mornings is P&EOG still the most effective hypermiling technique? Or is it better to get to operating temps quicker with P&G or steady throttle?

There are a few reasons for reduced fuel economy when the engine is cold. One of them is that the engine parts have contracted as they've cooled and you end up with increased blow-by and relatively loose clearances.

Because of this, I would personally recommend steady state. Most of the time I don't force the engine to pull further than the torque peak as long as the temp gauge is still buried in the cold.

Nice job on the term PEOG. I haven't seen it before, but it's every bit as good as my idea of calling it P&EOC. No matter what, it's good to differentiate between engine-on P&G and engine-off P&G.

I think the lower temperature doesn't change what is the most fuel-efficient strategy, but it does bring other concerns such as warm-up, increased clearance as mentioned above, etc. Looking at FE only, whatever was best before is probably still going to be best.

My VW takes forever to warm up no matter what, although I suppose I could flog the hell out of it and warm it up faster. With reasonable driving, whether hypermiling or driving like everyone else, full grille block or none, it won't warm up until I get on the highway 7 miles (15 minutes) down the road...usually a mile on the highway before heat is useful.

It's -15. I let it idle 7-10 minutes, otherwise my breath frosts the window over faster than it takes to warm up enough to keep clear. I need more blockage, as even when its warm its only 175, far too cold right now. I usually drive a steady rate, keeping it around 2000rpms. I also use a large vinyl fabric--soft on one side, vinyl on the other--to keep external frost off the windshield. A nice by product is all the heat that flows out of the hood vents is it stays on the window, decreasing warm-up times slightly, and allows me to drive sooner since the window is clear.

The 7-10 minutes of idling must be great on gas...

If you get a 30 dollar block heater, and plug it 2 hours before you use your car, u will be able to start driving it right of the bat. Get a timer if its morning use, but idling is the less FE thing u can do, also its not ecological at all.

P&EOC or whatever you call it is the best strategy for fuel usage. If you want heat, it's the worst strategy. Take your pick - low fuel or warm engine. Any driving style that warms it up faster also burns more fuel, and it will NOT be recovered by better mileage later. I've tested this.

I'd take a look at the thermostat if it's taking that long to get warmish, possibly stuck open, or not fully closing.

I found 0W30 oil helps a lot in winter, I have only 4 blocks to drive before hitting the highway on ramp. With regular oil in cold weather, the car is still very sluggish and it feels "bad for it" in accelerating up to highway speed before the oil is fully warm and it's in closed loop. With 0W30, it feels good within 30 seconds or 1 block.

Who are you talking to here? Honda's take notoriously long to warm up. But my friend's lexus takes about 1.5 minutes. I'm simply amazed at the difference.

Sounds like thinsulate it is!!!

I had no idea they were so cheap. I'll be looking for one now...

Block heater

Wikipedia... https://en.wikipedia.org/wiki/Block_heater

How to install ? https://ecomodder.com/forum/showthrea...stall-765.html

Where to buy? https://www.hondacarforum.com/honda-t...ck-heater.html

HAHA the how to install is present by Tomo, but on eccomoder.com! Find out after putting the link... its 100% legit so... :D

I think Lexus must have a intake baffle that crosses the exhaust manifold, hot air helps heat up an engine quickly, in Scotland right now its minus 7 degrees Celsius, I just by passed my radiator as I only do short journeys under 5 miles each way, I still haven't found a cheap system to recover the heat from all the hot water which is being wasted into the atmosphere, I heard BMW and HONDA have developed engines that have no radiators, this will be a big area for energy recovery.

lexus does not cross the intake over the exhaust manifold. that's something that went away with the 80s even in domestics... they just have the engines tuned really high output. typically higher hp/l means more heat/faster warmup.

I do not have any idea about the best strategy. Here is just how my cars are working with cold temperatures :
I have heaters in my cars (diesel) without knowing it
The scenic, always with her nearly full grill block, is hot at 10km (6 miles). The megane, with its grill block fully removed, is hot at 12-15km (7-9 miles).
Now my SGII isn't compatible with my cars so I'm referring to the temperature gauge needle on my dashboard.

Denis.

also these "high end" cars use a two stage thermostat. these will route heat from just the head to the heater till the engine is warmed up then the block portion opens up. older vehicles use a whole engine thermostat. the Head sees heat before any other part of the engine so that is why the lexus seems to be warm faster it actually isn't but the perception is there.

A block heater should be a good thing.
I haven't installed one (because I do mostly fairly long one hour commute trips) but I've read enough favorable posts by hypermilers who use them. They're especially good if medium or short length trips are what you do most - because a high percentage of your drive time + distance is spent heating up the engine.

I definitely recommend a grill block. Even with a block heater, driving through the cold winter air steadily washes cold air over the engine, causing you to continually spend fuel replacing that lost heat.

And be sure the thermostat is working properly. My ScanGauge shows engine temp much more precisely than the simple dash gauge. I know the '90 Civic won't support a ScanGauge but my point is, just because the gauge needle eventually gets up to the center don't assume the t'stat is working right.

Pics of my grill block. My car does warm up much quicker with the grill block in. I used foam pipe insulation. Some of it is hot-glued into position.
https://www.fuelly.com/attachments/fo...35f2122313.jpg

https://www.fuelly.com/attachments/fo...6714ee2a5b.jpg

I'm gearing towards remote start in my car but have any others in apartments come up with a way to get their car plugged in or pre-heated?

Since I've started this thread I installed a block heater. I have the same issue with my car here at work since there isn't a place to plug it in. Today, I'm going to take a walk around my business park (boo hoo to 24*F) and look at every light pole to see if any of them have an outlet. If I can find one it may mean that I'll need to walk a little farther to get in doors but it will be worth it.

By the way I installed remote start in my wife's car b/c I don't trust her with a block heater.


**Ring Ring**
Me: Hey love, what's going on?
Wife: Hey I'm driving now and was wondering what to do if I forgot to take the cord out.
Me: What cord?
Wife: You know that orange cord? It's still plugged into my car.
Me: And you're driving it?!?!?


Let's just hope we don't get a Civic GX that hooks up to our house's natural natural gas line!:eek: :eek: :eek:

My friends wife has a new Nissan Rouge and is wondering why her mileage is going lower now getting 25 instead of the 26mpg when new. I said you use the remote starter too much!

I find that when I leave his home there is a long up hill drive and taking it at about 10 mph in a high gear really lugging the engine at about 1000 rpm or less gets the engine warmed up pretty quick. It allows more time for all the heat of the combustion to be absorbed in the block and pistons before it leaves to the exhaust. I defineately see more heating of my engine when pulling up a hill than coasting or engine braking. Just this morning I was at 181 degrees and turned the heater on low and dropped the engine temp to 172 and it also raised the idle and increased the fuel consumption at idle.

I believe that part of the dip in my wintertime MPG is due to my remote start. Since I leave my house at 4:45 wearing gym shorts, I start the car for 5-10 minutes beforehand. It's a nice luxury but does require some fuel.

Be careful about too much lugging on a cold engine, your crank & rod bearings might not like it. I'd rather you keep the RPMs up and load down, for better engine longevity.

-BC

The only problem with leaving the engine revved up is that the water pump starts going and more water bypasses the thermostat.

I'd more worry about getting a cold engine up to temp too fast by lugging it like that. As long as he has oil pressure the rod bearings should be fine.

We don't need no stinking oil pressure I have Synlube - the solid lubricant. Yeah guys the 1.5 liter doesn't strain that much - granted the vacuum is probably pretty low but I don't have the pedal to the floor - I think fuel rate is about 1.5gph or less. If I end up going there tonight and staying over I will see what I pull tomorrow morning in single digit temps. I don't make a habbit of climbing the hill that way but I did notice that it seemed to warm up pretty quick.

OK 1000 rpm third gear 1.0gph fuel burn rate temperature rose from about 40F to 93F up the hill outside temps 17F air intake according to Scangauge. Man what a mpg hit I took this morning - the low was 6 degrees. Once I got warmed up for the second leg of the trip into Newport this morning I managed 45.6mpg but I started out at 27mpg for the first several miles. Going slow it definately better for mileage in really cold weather.