Question re: Oil Volume and Operating Temperature

[Shel_B]

I drive a lot of short trips at low speed and low stress on the engine. Now that the weather is getting colder it seems that the oil in the sump would take longer to reach operating temp. If I filled the engine with 4 quarts instead of 5 quarts, or maybe even 3.5 quarts, would it get to operating temp quicker than with the full capacity in the sump? Might that not reduce dilution from condensation and fuel dilution, and perhaps provide better protection and less wear?

Most of the time I'm driving only five miles a day, broken into two trips, rarely exceeding 30mph / 1500rpm.

 

[Jetronic]

it won't do much for the coolant to reach operating temp, and cool coolant causes more fuel dilution. On the other hand, you might get the same fuel in less oil, increasing it's concentration.

Your distances aren't enough to make the fuel evaporate from the oil again.

 

[barryh]

Because I do low annual miles I run both my vehicles just a little above minimum on the dipstick for much the same reasons you are suggesting i.e. it will warm up faster. The manufactures are happy as long as it's above min and I'm happy it will stay above min because I know from long experience that they burn a negligible amount of oil between changes so why not. Filling to max and then changing in in a few thousand miles is just a waste of quality oil when the sump capacity was designed to do several times more miles than I'm actually doing

 

[kschachn]

The best "protection" is that it resists oxidation and sludge formation, especially in low-use vehicles. By deliberately reducing the oil volume you're only hindering that protection and not helping it. Oil quantity is your friend not the enemy.

I can't imagine lowering the quantity by 1 or 1.5 quarts for any reason whatsoever. There is no good reason to do so. If you really, really want the oil to warm up faster then use a thicker grade.

 

[barryh]

On the subject of oil contamination, I've spent the last 14 winters doing a short motorcycle commute and being an air cooled engine this is very much a worse case scenario as it's massively over cooled in low ambient temperatures. I know from measurements that the oil doesn't get any where near a decent operating temperature and left to it's own devices will produce mayonnaise in the cooler parts of the engine e.g. inside the rocker covers. I learnt quickly that a simple solution was to let the engine breath. On arriving home and parking in the garage I unscrew the dipstick and leave it overnight. The oil will be at no more than 60 deg C in the sump but that's enough to drive off any moisture from that days trip and when done every day it prevented the creation of mayonnaise. I appreciate it's a lot easier to do this on a motorcycle as it takes only a few seconds but I suspect it would work for a car if you went to the trouble to do it.

 

[wpod]

Are we really serious?

 

[PimTac]

Why not just drive a longer distance?

 

[kschachn]

On the subject of oil contamination, I've spent the last 14 winters doing a short motorcycle commute and being an air cooled engine this is very much a worse case scenario as it's massively over cooled in low ambient temperatures. I know from measurements that the oil doesn't get any where near a decent operating temperature and left to it's own devices will produce mayonnaise in the cooler parts of the engine e.g. inside the rocker covers. I learnt quickly that a simple solution was to let the engine breath. On arriving home and parking in the garage I unscrew the dipstick and leave it overnight. The oil will be at no more than 60 deg C in the sump but that's enough to drive off any moisture from that days trip and when done every day it prevented the creation of mayonnaise. I appreciate it's a lot easier to do this on a motorcycle as it takes only a few seconds but I suspect it would work for a car if you went to the trouble to do it.

One would guess it prevents "mayonnaise" formation on the underside of cap since it is removed and sitting aside, but in terms of actually reducing the amount of moisture present in the oil that's an entirely different situation.

 

[tyman]

Wait, what?

 

[gfh77665]

Don't try to out think the vehicles design. The cooling system and oil volume is not influenced by outside agendas like viscosities are by CAFE.

This is one area where the engineers really do know best. Keep it full to the proper level.

 

[wpod]

Why not just drive a longer distance?

Buy an electric car?

 

[PimTac]

Buy an electric car?

It would be a good choice but the costs might not be worth it with those miles. The OP may be in a quandary here.

 

[OilUzer]

if I were that concerned, I would get a block heater or driver a little sooner (vs. Idle) and/or longer. maybe don't go to overdrive or use the highest gear when cursing and keep the rpm higher once warmed up ....

Some people get a deeper pan (more common with ATF) to increase the oil volume ... I would never decrease any oil volume.

Thicker oil should theoretically help but I can't recall how significant it is. Higher W should speed up the warm-up and thicker viscosity grade in general should increase the operating temperatures. I recall something like 10-15°F increase in operating temps if you move up from 20 to 30 grade but not sure. Maybe someone else has some data or examples.

Easiest thing would be to keep the rpm higher. No OD and/or avoid the highest gear(s) as long as your TC is locked i.e. I wouldn't do 60-70mph in 3rd gear. My car is 6 spd auto and doesn't lock in 3rd under normal conditions. 4th is my favorite to get things warmed up.

 

[barryh]

Why not just drive a longer distance?

What you want me to take the long way around to work riding a motorcycle at - 5 Deg C. You have to be kidding, it's too cold and would make little difference as an air cooled engine will always be overcooled in the winter.
I do what I can to minimise the problem and I have 14 years of experience that says it works and reduces contamination of the oil. I do very short OCI's as well of course. The other options are walk or abuse the car instead. I do walk when it snows.

 

[ocoilslick]

Interesting thought process. Might work to some extent on some certain vintage type car. What kind of car you talking about in the SF Bay Area that rarely drops below freezing? I would invest in some sort of block heater before I tried to re-engineer the car.

 

[ZeeOSix]

Put a dyno in the garage and do 10 or 12 pulls to redline ... that will get the oil warmed up.

But seriously, all you can do is just make your drives longer. I wouldn't run the oil level low in hopes it's going to help warm up the oil more ... not going to make any real difference in your case. Your 2011 Camery probably has a coolant-to-oil cooler, and if so maybe you can block off the radiator some with cardboard to make the cooling system run a bit warmer if you're in a very cold climate, and therefore the oil heat exchanger may in turn get the oil a bit warmer.

 

[Blinker]

What you want me to take the long way around to work riding a motorcycle at - 5 Deg C. You have to be kidding, it's too cold and would make little difference as an air cooled engine will always be overcooled in the winter.
I do what I can to minimise the problem and I have 14 years of experience that says it works and reduces contamination of the oil. I do very short OCI's as well of course. The other options are walk or abuse the car instead. I do walk when it snows.

I think PimTac was referring to the OP, not you.

 

[Flyingdutchman]

With less oil in the sump the oil will also dillute faster at a higher percentage rate.

I would also see for an electric block heather.

Is this a pretty modern engine or an older style engine.
Modern engines with their vvt, collant to oil heat exchangers do a pretty good job.

Most modern cars also have a closed underpanel under the engine bay.

I dont know if you car also has one. Otherwise it might be an option to make one. This helps the engine/tranny with warming up and also holds the heat in it a little longer.

 

[DGXR]

Yes a smaller quantity of oil will heat up faster but will also be worn out faster so consider that in your maintenance schedule. If your engine does not consume or leak oil and you don't work it too hard (hauling/towing/racing), you can safely fill it to the lower end of the dipstick -- as long as it's between the two marks then the level is OK. I've done this many times on my Tacoma with zero issues -- that is a 4 cylinder with a 6-quart capacity.

Probably related but not sure: I recently saw a video where an engine reliably produced significantly less power on the dyno when the oil was filled all the way to the top mark. The problem was with the crank throws dipping into the oil (even slightly) and whipping air into the oil, which the oil pump does not like and the engine bearings like even less. This shouldn't happen if the oil level is between the two marks on the dipstick so maybe their engine's dipstick was faulty? But while we are talking about oil levels I wanted to toss that in FWIW.

I strongly believe it's unnecessary to keep the oil level perfectly topped up. If it's low, sure go ahead and add a quart. If you have an oil burner/leaker, then obviously you want as much oil in there as safely possible. But if the engine is healthy and the oil level is only 5mm below the top mark, there is absolutely no reason to do anything. It's fine.

 

[ZeeOSix]

Probably related but not sure: I recently saw a video where an engine reliably produced significantly less power on the dyno when the oil was filled all the way to the top mark. The problem was with the crank throws dipping into the oil (even slightly) and whipping air into the oil, which the oil pump does not like and the engine bearings like even less.

A properly designed engine shouldn't have the crank throws getting anywhere close dipping in to the oil level if it's not overfilled per dipstick "full" mark. Engines also have a windage tray in the oil pan, and if properly designed it will help to keep the air "hurricane" caused by the crankshaft and pistons from disturbing the oil in the sump.