Heavier oil weights in hot climates??

[dlundblad]

More specifically, in liquid cooled engines..

I read a lot here how people say something like "oh you live in Florida.. you could get away with running say a 5w30 vs a 5w20. Granted the thicker oil wont hurt anything, but take away a split frog hairs worth of fuel economy (and maybe void a warranty). I just feel the reasoning (air temperature) is wrong. Am I missing something?

And just to explain myself better, if I drove say an oil consuming Chrysler 3.8 in Florida, I would be more inclined to run a 15w40 year round rather than the specified 5w20 if I lived in say an Indiana climate.. only because it would slow consumption while taking the engine less time to get the oil to operating temp. This reasoning is based off of consumption.. not protection against wear.

The way I see it, thicker weights aid consumption.. not offer better protection in heat. Am I correct?

 

[hatt]

If you're running a heavier oil to combat consumption then obviously your reason for running the heavier oil to to aid consumption.

 

[Shannow]

10cst will always provide a greater parts separation than 7cst...

whether that provides more protection is debatable, as the later may or may not be operating in boundary lubrication conditions somewhere in the engine (maybe in a nook/cranny). If it is, then the thicker oil will provide greater protection.

Given that the thermostat and cooling system control the viscosity at the operational temperature of 100C give or take, then 7 or 10 means nothing in terms of wear, but which has more margin for error...the thicker having more margin, always.

What the higher ambient always does is remove any need to chase VI for engine protection. You may choose to choose increased VI for tinily better warmup fuel economy, and great.

Not needing to chase VI meand that you can choose an oil that is more predictable in terms of viscosity retention, and volatility over the OCI...so yes, I agree with your last para.

 

[Donald]

The owners manual typically lists a few temp scales and suggested oil weights for each scale. Why not follow what is in the owners manual? Or start there.

 

[tig1]

Two things.

1) It doesn't get all that hot in Florida.

2) 20wt oils perform very well in all air temps.

 

[dlundblad]

Originally Posted By: hatt
If you're running a heavier oil to combat consumption then obviously your reason for running the heavier oil to to aid consumption.


That is what I am saying in my first post. A common misconception here is that thicker weights protect more in hotter climates.

And to add to that: If your engine doesn't consume oil, a thicker weight isn't necessary.

 

[dlundblad]

Originally Posted By: tig1
Two things.

1) It doesn't get all that hot in Florida.

2) 20wt oils perform very well in all air temps.


I was just using Florida as an example. Read around a bit and you'll see Mexico and the all of the south west are also used as examples.

 

[hatt]

Originally Posted By: dlundblad
Originally Posted By: hatt
If you're running a heavier oil to combat consumption then obviously your reason for running the heavier oil to to aid consumption.


That is what I am saying in my first post. A common misconception here is that thicker weights protect more in hotter climates.

And to add to that: If your engine doesn't consume oil, a thicker weight isn't necessary.

Engine protection is debatable. If heavier oil helps your consumption issues that's pretty clear; but doesn't say anything to the better protection issue.

 

[Oil Changer]

It's the BITOG way. Members will consent to the use of lighter oils in colder climates then defend-to-the-death following the OM in warm climates. Go figure.

 

[Oil Changer]

AH! That's funny.

Originally Posted By: Shannow
somewhere in the engine (maybe in a nook/cranny).

 

[dlundblad]

Originally Posted By: hatt
Originally Posted By: dlundblad
Originally Posted By: hatt
If you're running a heavier oil to combat consumption then obviously your reason for running the heavier oil to to aid consumption.


That is what I am saying in my first post. A common misconception here is that thicker weights protect more in hotter climates.

And to add to that: If your engine doesn't consume oil, a thicker weight isn't necessary.

Engine protection is debatable. If heavier oil helps your consumption issues that's pretty clear; but doesn't say anything to the better protection issue.


Pardon? Read the last line of the first post.

 

[hatt]

Originally Posted By: dlundblad


Pardon? Read the last line of the first post.
Just because you said something doesn't settle the debate.

If you want to get down to it. If you believe heavier oil generally lowers consumption then heavier oil does offer increased engine protection to the avg consumer who never even thinks of checking the oil.

 

[dlundblad]

Originally Posted By: hatt
Originally Posted By: dlundblad


Pardon? Read the last line of the first post.
Just because you said something doesn't settle the debate.

If you want to get down to it. If you believe heavier oil generally lowers consumption then heavier oil does offer increased engine protection to the avg consumer who never even thinks of checking the oil.


This is a debate now? Are you one of the Florida people that run 15w40 in a 4 cylinder?

* And IIRC, we aren't discussing the average consumer who doesn't check their oil. BITOGERS check oil frequently.

 

[hatt]

LOL. I see what you did there. I'm heading out to ride my mountain bike. The weather today is unbelievable. So cool I may have to change out that 10W-30.

 

[Hyde244]

Originally Posted By: tig1
Two things.

1) It doesn't get all that hot in Florida.

2) 20wt oils perform very well in all air temps.
+1

I'd say just stick to the manual, unless you are seeing oil consumption where thicker oils can help. As to engine protection - all modern oils will do more than enough to protect in a normal application.

 

[dlundblad]

Originally Posted By: hatt
LOL. I see what you did there. I'm heading out to ride my mountain bike. The weather today is unbelievable. So cool I may have to change out that 10W-30.


Im jealous. I have to go to work in an hour.

Next Thursday I'm hoping to hit some trails.

 

[hattaresguy]

On a liquid cooled engine it shouldn't matter, the coolant and T state keep the motor at the same operating temperature regardless of exterior temperature.

Stick with the manufactures recommendations, they do hot weather testing.

Most modern cars spec a 20wt oil and I don't see piles of them in FL junk yards because its to light.

 

[05foresterXT]

The owner's manual for my Forester recommends the use of SAE 30, SAE 40, 20w50, for use in high stress applications such as driving in desert climates and towing. It also has a chart showing 10w30 and 10w40 being recommended for all temperatures above 10 degrees F, and 5w30 being recommended for all ambient temperatures. I honestly do not know the reasons for the heavier oil recommendations in hot climates. I wonder if they specifically made the oil section impossible to understand so any mechanical failures can be attributed to using the wrong oil.

 

[kr_bitog]

IMO, Heavier oil weights provides bigger margin for overheated engine, fuel dilution and oil shear due to extreme driving in hot climate. If the car is driven lightly, the heavier weight have no benefit except reducing oil consumption on engine that burns oil.

 

[Ken2]

Quote:
if I drove say an oil consuming Chrysler 3.8
Why is it consuming oil? Glopped up PCV? Thicker oil isn't the answer. Carboned piston rings?--not the best answer. Leaking valve seals?--not the best. Leak when driving?--little or no help. Worn piston rings?--rare these days, but now thick oil is a help.