Oil temp
 

After having an oil temp gauge for a while now I have some data for WHEN my car is fully up to temp, ie- when it STARTS getting good mileage.

As we all know the coolant temp comes up quick, less than 2 miles even on a cold day, but the oil temp lags way behind. On a 70f day it usually takes around 15 miles to get the oil up to 180f or so and that temp is when my car starts getting good mileage.

This morning I did a 49 mile trip with a starting temp of 39f and ending temp of 43f. The oil took 35 miles to get to 180f! I struggled to get over 35 mpg during oil warmup, but brought it up to 39 mpg by the time I finished the trip.

Had seen this trend developing the past few tanks as cooler weather arrived.
This morning after the trip I took the belly pan off and insulted the oil filter and oil pan. Both are in the air flow at the bottom of the radiator shroud so that does explain why it takes so long to get up to temp.

Will know Monday morning how well it works but am looking for another solution just in case the temps get too hot, or 212f+.

By the way, on 80f days the oil temp only runs 185-193f, or about 5f over coolant temp.

Thanks for the data!

But sorry Harvey, I just can't pass this one up! :p You insulted your oil filter and pan? They might get hot under the collar now!

What kind of oil are you using? Dino or synthetic? What viscosity grade? Is the one recommended fer yer vehicle? ;)

Snap some piccies of what you did to insulate yer oil filter and oil pan. :D

Frank, :D.

So then an oil pan warmer might produce better fe than a block warmer. I wonder if this is in part caused by oil viscosity? The 212 oil temp is that the spec for your car? I know this is a general rule for block temp.

Yes I think it is actually entirely caused by oil viscosity. I've been reading bobistheoilguy and apparently the difference in oil pressure at startup is as much as 20 psi between different 0W-20 rated oils, with Toyota's 0W-20 having the highest viscosity index. Maybe I read it wrong, but someone definitely posted saying that their oil pressure dropped 20psi when switching to Toyota 0W-20, and I don't think they were going from a 40 or 50 weight oil either. In fact Toyota's 0W-20 is so good that some people there apparently recommend adding some as "viscosity index improver". Seems like a thinner oil is the easiest way to get better gas mileage on shorter trips.

100C is a typical temperature for listing the oil viscosity at, I think it's considered the "correct" temperature.

Perhaps a good fuel economy addition could be an oil to water oil cooler. "Coolers" are usually used to reduce oil temp on the track, but obviously if the water is hotter than the oil, then the water will heat the oil up :D

Good catch Frank!

Oil spec is 5w20 or 10w30, dino or syn. Running Pennzoil Ultra 5w20 and have no idea what the spec is for oil temp, but the sender is also the drain plug so it's reading average sump temps. Oil viscosity is based on 212f, so I'd rather run a shade cooler (thicker) than too hot (thin).

Basically, I wrapped the filter with header wrap and aluminum INSULATION tape, and then used a small soldering blanket which is like header wrap for the pan.

BITOG is a great site.

If your car is designed around a 8.5cst (xW 20) oil at an oil temp of 212f, then at 104f the oil is 30-48 cst, or WAY thicker than even a xW60 at 212f.
Too thick and it kills mpg...

My diesel has an "oil cooler" in the radiator that flows oil all the time. It brings the oil up to temperature with the coolant.
Sounds like you need something like that.

Or you might want something like this:
Epic oil pan heater w/pics - Diesel Place : Chevrolet and GMC Diesel Truck Forums
Has pics

Oil pan heaters. The magnetic ones are fairly cheap and work well... providing you have a steel oil pan.

Been running Toyota 0w20 for the last 100000kms, year round. Mind you, my engine's spec'd for it.

BTW, it was -16C this morning... so enjoy your warm southern temps!

Thanks for this, guys.

I'm watching with distress as my mileage keeps dropping as the temps drop and I'm doing less highway testing. Because of these short trips, I'm thinking I should get some sort of engine pre-heater. I'm thinking about one of those KAT's silicone "pad" heaters for the bottom of the oil pan (150 watt), AND one of the coolant type heaters that is installed by cutting the lower radiator hose and fitting it in there.

Any advice? Would this be enough? - too much? - potential problems?

Oh, and I had my ScanGauge set to display water temp & noticed when I first started my car this morning, both the outside air temp and coolant temp were in the low 40's. I hit my stopwatch when the engine started & took off. In a few blocks of city driving (EOC at stoplights), it took 3.5 minutes for the water to reach 100 deg. F. and after about 5 minutes (when I reached my destination), it was only at around 125 deg. F. or so. Does this sound "normal"? This afternoon, in some longer duration operation, it seemed to stabilize at around 172 deg. Wondering if I should be concerned about my thermostat or anything???

Thanx in advance...

I wonder if one could use one of those portable induction cooktops to heat up the oil with... ;)

I guess I'll have to see what it would take to heat up the oil pan with one... :D

Portable induction cooktops to heat up the oil, it's just amazing the ideas this site generates. :thumbup:

Hopefully it won't cook the oil. :rolleyes:

...put new meaning into the term "Baked Alaska (oil)" wouldn't it? :thumbup:

Since induction heating is so efficient...one would expect it to outperform the standard radiating coil types. Looking to find a broken induction top so I can strip it down and embed the coil on the outside of the oil pan. Place a rubber mat between the element coil and the pan to keep the vibration from destroying the element coil. The only problem would be is that the control panel doesn't allow fer auto on when the power is plugged in so using a timer to start it might be out of the question. I'll have to do some brainstorming to bypass that some how...maybe a relay system. Who knows. ;)

I'll have to do an experiment to see how quickly the oil will come to temp. Maybe an old oil pan filled with 5 quarts of motor oil and placed on top of the induction burner. Time how long it takes fer the oil to hit the upper temps and when it starts to level out. Maybe sample the temp at 2 minute intervals along with the ambient temp. :D

If this works...could you imagine using an induction heater setup on an iron engine block to preheat the coolant? Even something like an iron reservoir that was plumbed into the cooling system might work, too. :D

I think the idea is great.

Title for the thread. "How to cook your way to better MPG";)


To warm the coolant a ferromagnetic material sleeve could be added to the lower radiator hose and a unit attached there.

Rubber might get nasty if it gets too hot.

wow, i guess i need to delete my oil cooler, or maybe just relocate it inside the engine bay for winter.

Just cover it. Even something like tin foil would work.

I believe this myself and have said it before with little support. As you say the oil comes up to temp so slow and the head is where the combustion is so it comes up fast.

Just acedotal but my mom lives on top of a hill and there is a huge noticible difference in engine braking (& injectors off) going down that decline on a just started engine vs an up to temp one. The only factor involved is oil viscosity.

I see it on my scangauge too, air temperature is irrelevant on my idle fuel economy, its all coolant and oil temp, I did see a difference too when I changed oils from summer to winter oil.

You might also try a thermostat in the oil line to bypass the cooler until the temps are getting up there.

Peter.

Just picked up broken induction burner off of eBay. They said the top was broken and the electronics should be working. We'll see when it gits here. ;)

So I had this crazy idea...install a stainless steel box under the oil pan and plumb it into the cooling system. With the induction coil installed under the coolant box, it should heat up the coolant and the oil at the same time and keep the burner from "frying" the engine oil. My engine bay belly pan should keep anything from puncturing the added coolant box. Heck...it might even keep the oil temps from rising too far, too! :D

Not sure how I'm gonna mount it to the bottom of the oil pan though. I'm not sure that I should try to use any of the oil pan fasteners to secure it to the engine.

When I was in college (late 90's) we had done a lab experiment with engine oil viscosity. IIRC, we used a conventional 10W-30 and a synthetic 10W-30, chilled both to -45°F (We just left them outside overnight...) and measured the viscosity as we slowly heated to 212°F.

Even though both were the same viscosity rating, there was a huge difference at extreme temperatures. I've forgotten the numbers exactly, but remember the synthetic being similar in consistency to honey at -40°F, but the conventional oil was VERY thick, almost a solid, kind of like Silly Putty.

Even at room temperature, there was a big difference between synthetic and conventional. It wasn't until it got close to boiling (of water) that they were about the same.

I was an original member at BITOG. In a discussion years ago on oil pan heaters the concern was raised about cooking the oil (hot spot) and, IIRC, the admonition was to avoid temps above 150F as well as careful control of time. This advice was from one of the brainy types who left long ago (there is a lot of junk to wade through over there now). I would be (and will be, as one of these is on my list) careful about overheating. Just getting the oil above 100F evenly (how to measure, the problem) would be enough, IMO.

Yes, it takes quite a few miles to get engine oil to op temp. And the oil-to-coolant exchangers are also in place to quickly rid the oil of heat spikes which otherwise reduce lubrication effectiveness. That is likely a more important function as it is "life saving".

I would be cautious about pushing pre-heating too far. Not much. I've looked at the immersion heaters and would carefully consult about size and use with the manufacturer prior to purchase.

.

Got the broken induction burner in and started taking it apart. I think it's gonna work just fine... :D

Broken ceramic/glass top...
http://i677.photobucket.com/albums/v...r/IMG_1822.jpg

Top removed...
http://i677.photobucket.com/albums/v...r/IMG_1823.jpg

Induction coil and temp sensor removed...
http://i677.photobucket.com/albums/v...r/IMG_1824.jpg

Bottom of induction coil and temp sensor...
http://i677.photobucket.com/albums/v...r/IMG_1825.jpg

Thickness of the induction coil...
http://i677.photobucket.com/albums/v...r/IMG_1826.jpg

I should be able to hook up some extra wire to the induction coil. It looks like 12 or 10 gauge wire and a simple 2 wire connector should work. This will allow me to only place the induction coil under the item I want to heat up (oil pan or coolant pan) and keep the electronics portion out from under the hood.

I'm thinking of using two glass cutting boards to sandwich the induction coil with so the coil won't git banged up as I'm moving it in/out of the area. I guess I could use some Luan pieces instead since the coil won't need to "cook" anything... ;)

I wouldnt worry too much , because where your sender is might be cooler , hard to figure exactly where to mount one, because the temp will never be the same though out the engine, I am thinking the main reason your milage goes up is the oil pump itself takes quite a bit of power to spin , another reason low revs are good , but good info all around, i like the idea of wrapping the oil filter, seems logical and not too radical , otherwise the only way out is to install an oil cooler which on most cars now is tricky to run properly ,

oil temp
 

For years I have felt that allowing the engine to run for a minute or so (no a half hour!) before driving in cold weather delivered better FE. I have no way to prove it under controlled conditions and have to rely on observing MPG / conditions. Many argue that allowing an engine to idle is a pure waste because it is burning fuel without moving the vehicle. While this is true, there may be a synergistic effect that isn't so obvious like warming the oil and reducing engine drag.

I often think of the winglets on the ends of an airplanes wings. They provide no lift, they increase drag, but they make the wing as a whole more efficient. Interactions can be less than obvious some times.

Does anyone have the time / equipment / inclination to determine air temp, oil temp, fuel consumption rate vs time? That might show some huge insight into what we all are fighting.

Did anyone ask the OP how and where he measured the oil temp? this could be why they are not seeing the oil temp increase over a long or short distance.

using fuel to do no work(beyond heating up the heads/block) will result in more fuel consumed.... that being said, idling for 60 seconds and taking off on a ~50 mile trip, the difference is probably within the margin of error for calculating fuel economy based on full tank fills/empties. idling for 60 seconds, then driving for 60 seconds, you could see a ~30% increase in fuel usage....

it's all relative.



i would much rather idle for 60 seconds(probably more) after startup when cold and be assured that enough oil is getting where it needs to be than starting and being mobile within 5 seconds of letting go of the key. a lot easier to replace some fuel than it is to replace the engine.

This is one area where adding the two cycle oil will help since it leaves a film of lubricant that should help on start up on the piston rings etc, my ranger seems smoother on cold start now since adding it to the fuel .

oil temp vs fuel consumption
 

I guess the question I would like to see a definitive answer to is:

Is the fuel consumed in running an engine at idle for a minute more than offset by the reduction in fuel consumed because of the warmer oil?

Yes, obviously the fuel consumed is "wasted" because it doesn't move you down the road, like the example of the winglets on the airliners. They add drag, they produce no lift therefore they are bad, right? Wrong, they improve the lift by keeping the airflow over / under the wing without it slipping off the end of the wing. Can the fuel burnt by idling the engine a minute improve the efficiency when the engine is under load enough to pay for itself?

I run 5W20 in the Ranger and the Fiesta. I never let the engine run without getting moving. I will pulse and coast (engine on), even in the first .3 mile out of my neighborhood.
After sitting a week my 1937 Ford flathead coupe would produce 60 PSI of oil pressure in 5 seconds of cranking (it had a starter button for ignition off). Thats a direct drive 6 volt starter cranking at 100 RPM, less than 10 revolutions of the engine.
The cranking speed of most modern cars is about 300 RPM. which means you get the same pressure in 1/3rd the time, or less than 2 seconds.

regards
Mech

It shouldn't be too hard to test. Either with a ScanGauge or without. Start up the car & take off without warming it up & drive it for 5-10 minutes or so on a given route, come home & park. Next morning, repeat. Next morning, repeat again. Etc. Check mileage. Then do it again, but let "warm up" for 1 minute (60 seconds on the stopwatch) each time before taking off. Check mileage. And there will be the answer - It'll either help, hurt, or have "inconclusive results"?

With a ScanGauge, just do a "trip" average "current-reset" each time & note it. Then you can even spend the rest of the day driving "normally". But check it each time you do a cold start in the "morning".

Without a ScanGauge, there would probably have to be about 10 cold starts & drives on 10 different days for each the "no warm-up" and "with warm-up" tests checking mileage at the gas station when filling up. Obviously, it would be very important to drive the exact same number of identical trips for each the "warm-up" and "no warm-up" halves of the test and to fill up to the exact same level both times - same station, same pump, same time of day, etc, etc,

earlier today I started the truck and it idled cold at around 1300 rpm, when i switched on the fan to full it dropped at least 100 rpm, so a bit of load there, could that change the mileage a bit to run with only normal draft air and no fan, should be about 1/10 HP difference if the fans on high . some one else posted something about this somewhere. and Happy new year Guys and Girls . May all your trips be downhill and downwind.

I'm pretty sure idling to heat the oil is going to burn more fuel, because most of the heat energy of the engine goes out the tailpipe, not the coolant and oil. When you idle to heat the engine, you transfer maybe 20-30% of the fuel's heat energy into the engine. When you drive the car, you get that, the extra losses from pumping the cold oil (converting some of the 25-35% of the net mechanical work into heat via friction, dumping it directly into the oil), and you use the engine to do useful work at the same time. You get more efficient heating of the oil when the engine is cold this way, that is you have more fuel energy going into heating the oil, which is energy that you cannot get out of investing every time the car is driven.

I've started to switch the engine off at stoplights when it's cold.

I understand - and I don't disagree. But rbrowning was saying he'd like to see definitive proof one way or the other. The intent of my reply was just to say, "It shouldn't be that hard to get definitive proof", and if I were to do the test, this is how I'd do it. - - - and I might - just for fun. I've got a ScanGauge, so doing a few "drive off immediately" cold starts (like I normally do), taking the same route out of the nieghborhood, and logging the mpg for the first 5 or 10 minutes of the trip vs doing the "one minute warmup" first, and THEN driving out of the neighborhood taking that same route shouldn't interfere with my daily life too much.

And then, hopefully, the results don't fall into the "inconclusive" region, and I can post my "definitive results" for everyone of "ooh" and "ahh" over. ;)