Subaru & PP

[Bendite]

I have a 06 Subaru Legacy Wagon 2.5i/NA motor.

I have used Pennzoil Platinum 5W30 from the start. The car runs great with the PP but it does burn 1QT on a 5000K OCI. I was told that the 2.5 motor will burn synthetic oil because they are thinner than regular oil. On my last oil change, I went with Castrol Synthetic Blend 5W30 and I have only burned about 1/2QT on this OCI.

The car runs smoother on the PP and I am wondering if there is any reason to not run the PP? I like the Castrol and the cold starts are fine with it but with the PP the motor purred a little more purry than with the Castrol.

Is it bad to burn that much oil...or is it bad, only if you don't check your oil levels?

Thanks in advance!

 

[JayhawkRoy]

Our 03 Subaru Legacy Wgn with the 2.5L engine burns about a quart in 7.5K interval. Our previous 2.2L engine never went through 1/2 qt per 5K miles, in more than 100K miles.

At least, PP burns less than Mobil 1, so I am pretty happy. Conventional and Mobil 1 seemed to burn the same amount of oil between change intervals. No reason to change and after your warranty is out, you can consider extending your interval. One qt per 5K miles is average to low, from what I have seen.

 

[Bendite]

I have a couple of subi wagons and they all burn a Qt and I don't think it's an issue but it seems like it burned less of the thicker oil. I guess 1 oil change is not enough evidence to back that claim up.

 

[Titan]

I have two Subaru 2.5's, NA. Neither consume a significant amount of PP, unless I'm running over 80 mph...then, they will consume a little. Stellar results out to at least 7500 miles on this combination, and WIX filter every other oil change.

 

[VK56VD]

I would continue using it and continue to check oil level. Does you manual specify 10w30 as being suitable for above freezing temps? It may be a bit thicker and may burn less than the 5w30.

 

[VK56VD]

Please disregard this post. I accidentally hit "enter" twice.

 

[Oilgal]

Why would that help? Don't both 5w30 and 10w30 behave as 30 weight oil at operating temps?

I am just asking. Just trying to learn here.

 

[Titan]

Originally Posted By: Oilgal
Why would that help? Don't both 5w30 and 10w30 behave as 30 weight oil at operating temps?

I am just asking. Just trying to learn here.

You are correct, both are in the "30 weight" range of viscosities at operating temperatures. More important would be the HTHS values, with regard to consumption. It's probably true that a non-synthetic 10-30 would tend to have a higher HTHS and lower volatility values than a similar 5-30.

There are all sorts of qualifiers that could affect the rate of consumption due to differences in HTHS and volatility, such as: if Pour Point Depressants were used to manufacture a particular 5-30, the base oil used in each case, etc...

In some engines, perhaps there is a greater mis-match in piston-to-cylinder wall clearances when cold, and some squeeze-by is occuring on every cold start-up; here, you might be able to decrease consumption with a 10-30 compared to a 5-30 if you have many cold starts.

I'm just saying if your car is consuming 5-30, you won't automatically see a decrease in consumption by going to a 10-30.

 

[Oilgal]

Thanks Titan.

Don't engines allow more blow by and leakage through valve stem seals, when an engine fully warmed up, is driven hard at higher rpm also? I imagine, taking into consideration those things you mentioned also, that during warm weather an increase in viscosity from 5w30 to 5w 40, may also be of some help.

Is that correct?

 

[Titan]

Warm or cold weather has less effect on oil temperature in modern engines than most people think.

 

[bluesubie]

Also, 10w30's probably have fewer viscosity index improvers.

Usually, the turbos burn a bit more oil. I have a turbo and a '99 Outback (n.a.). I try to run higher HTHS oils in both and/or add some 10w40.

Spartuss - N. American Subarus spec pretty much use any grade except xw20 and xw50 (although a couple of people here run xw20 in n.a. cars). 5w30 preferred for fuel economy, 10w30 and 10w40 recommended in high temps. SAE 30, 40, xw50 recommended in severe conditions.

1qt. per 1,000 miles was the old "acceptable" amount, but I think it went to 1/800 miles or something like that.

-Dennis

 

[Oilgal]

I was just reading what you wrote on this same topic, in another thread, regarding VIIs also, and so I guess I need to rethink that assumption of mine.

 

[Oilgal]

Oil cooled turbos 'do' raise oil temps though. I think they also have more blow by, because of increased cylinder pressure though, and that may more likely explain their high oil consumption rates.

I dunno.

 

[AndyH]

Originally Posted By: Oilgal
Oil cooled turbos 'do' raise oil temps though.

Maybe so...but how many turbo engines produced today are only cooled by oil? Not many (if any) I would guess.

 

[mechtech2]

Warm or cool weather has a HUGE difference in oil temps.
Try putting your hand on an oil pan in summer and winter, after 1/2 hour drive.

 

[bluesubie]

Originally Posted By: Oilgal
I was just reading what you wrote on this same topic, in another thread, regarding VIIs also, and so I guess I need to rethink that assumption of mine.

That Pablo guy is smart.

Also check Ed Hackett's comment in that thread about oil composition.

Just when you think you have everything figured out, a new oil or formulation comes along and changes the way everyone thinks about oil.

-Dennis

 

[Bendite]

Originally Posted By: Titan
I have two Subaru 2.5's, NA. Neither consume a significant amount of PP, unless I'm running over 80 mph...then, they will consume a little. Stellar results out to at least 7500 miles on this combination, and WIX filter every other oil change.


I do drive the car pretty hard and I am sure that burns a little more oil than it would if I shifted at 4K RPM. I defiantly have to check my oil regularly with the PP but I think I am going to use it again. Car just felt smoother with it in. Always WIX filters in my cars.

 

[Eddie]

I ran my 2000 forester S on Mobil 1 5w30 for 126,000 miles and sold it without any issues. Consumed ~ 1/8 to 1/4 quart of mobil 1 during a standard 6,000 mile oil change. A Blackstone UOA at ~30,000 and 90,000 showed outstanding results with the recomendation to try 7,000 OCI next time. Don't know what to think about PP except you are not the only one with PP issues.

 

[Dominic]

Mine burns 0.5qts in 5000. I fill with 5, get 4.5 out or so. It doesn't bother me any.