idle warm-up experiment

[rh77]

I plan on plugging-in year-round (or close to it). When it gets close to 100F outside, the garage gets pretty warm too, and it'll take a lot less time to reach NOT by driving in the heat. So I'll say maybe 8-10 months of use.

RH77

[GasSavers_worthywads]

I did a quick test awhile back and went on memory and got this.

engine
temp GPH
25F -- 1.9
45 -- 1.3
65 -- 1.1
85 -- .9
125 - .6
145 - .5
165 - .3
193 - .3

This was done while driving as opposed to idling in my driveway. I just dropped into neutral at each temperature to get the idle gph.

What I'm thinking of doing is making up a quick spreadsheet with 5F increments and get both a time and gph. I could get the intake air too but the tacoma has a pretty effective factory cold air intake, it doesn't climb much, wish it had a good old warm air intake off the exhaust like every other vehicle I've owned?

I've noticed I can get the engine temperature to drop very fast with the heat blasting, especially idling at an intersection. People that put their defrost on full blast and let their car warm up must never get close to fully warmed up. I'll let someone else do that test.

[krousdb]

It would be interesting if you also recorded the engine RPM while idling at those ECT's. The GPH figure is dependant on engine RPM so it would be nice to be able to divide the GPH figure by RPM. What you would end up with is a more linear graph that would be representitive of injector duration during warmup. Or maybe the scangauge can give you that directly?

[MetroMPG]

Originally Posted by worthywads

People that put their defrost on full blast and let their car warm up must never get close to fully warmed up. I'll let someone else do that test.

yes, it takes a certain amount of self control to leave the heater fan OFF on a really cold day until the temperature gauge starts to move!

(try explaining it to doubtful passengers: "really, we'll get heat faster if we leave it off for a minute or two... no, really! trust me!")

but i'll leave that test for someone else also...

[GasSavers_worthywads]

Originally Posted by krousdb

It would be interesting if you also recorded the engine RPM while idling at those ECT's. The GPH figure is dependant on engine RPM so it would be nice to be able to divide the GPH figure by RPM. What you would end up with is a more linear graph that would be representitive of injector duration during warmup. Or maybe the scangauge can give you that directly?

Don't know the exact temperatures, but my Tacoma will idle at 2000rpm if the temperature is in the 30-80F range but will drop quickly to 900 when the temperature gets above 120 or so.

What's weird is at temperatures around 10F it will idle at 1400rpm. So at some range it will idle lower at lower temperatures. I never just let it idle so I can't say if it would then climb to 2000rpm for another temperature range.

Recording the date I want may be a little too quick as is, I have a large faced stopwatch at work, the experiement will have to wait until I retrieve it.

[rh77]

Originally Posted by MetroMPG

...yes, it takes a certain amount of self control to leave the heater fan OFF on a really cold day until the temperature gauge starts to move!

Roger that. Driving home from the airport on a cold night (15-30F), I know that I leave the heater alone, things will heat up quicker. When I can't feel my fingers anymore, I move the lever halfway ;-) Actually this is partly true -- I get a little heat going in the cabin when it's to the "shiver" stage, then flip the temp control back to cold when there's enough heat to sustain another 10 mins. or so until I achieve torque lock-up, and leave it on comfortable heat. It doesn't lose heat like it used to with the old thermostat that was stuck open and now that I have a rad-baffle.

RH77

[GasSavers_worthywads]

"Fortunately" I need to dress warm for work so I can comfortably commute without using the heat at all. Just crack the window and exhaust my hot breath.

Toyota apparently hard wired it so that the A/C kicks on with defrost? On my Element I reprogrammed it so you can turn the A/C off if you choose, haven't found away to do this in the Toyota.

I did a dry run of my time/temp/gph data collection and decided one thing, every 5F is way to often for me to be able to record the data. I'm thinking now of every 15F, but do the same thing 3 different mornings to get every 5F through 3 passes.

As I've noticed the intake air temperature stayed a constant 30F the entire 10 miles.

[rh77]

Originally Posted by worthywads

As I've noticed the intake air temperature stayed a constant 30F the entire 10 miles.

You may benefit from a hot air intake. I installed one -- it seems to be the item that achieved the biggest increase in fuel economy (aside from driving slower, of course). I also have a hotter thermostat, that probably helps with the higher temps, but I generally get 120-140F intake air temp. When it gets warmer outside, I do notice some pinging/detonation, so I'll run the next grade-up of octane, since my vehicle doesn't have a knock sensor. Of course the down-side, is less power and some ECUs don't compensate (but I think Toyota's would).

RH77