High mileage WRX oil recommendations?

[edhackett]

Quote:
I re-checked my FSM to be sure, but It does say SJ "Energy Conserving" 5W30 for the recommended oil.


I'm not sure about the service manual, but as a past owner of a 2003 WRX, I can tell you for a fact that the 5w30 recommendation in the owner's manual is qualified "for best fuel economy". The next paragraph goes on to list, as bluesubie says, anything but a 5w30 if you are going to actually drive the car. 10w30 through 20W-50 is listed, including straight 30 and 40.

GC is a great choice, which I ran for quite a while. If you want to stick with shorter change intervals, Rotella T5 10w30 is a great choice. That's what I run in my 2008 LGT. There's no need to go heavier than a 15W40, but you do want to use an oil that has a HTHS viscosity of at least 3.5.

Ed

 

[Xstang]

Here's an interesting tidbit from the owner's manual:

5w30 is NOT to be used for sustained high-speed driving.
Suggestions are SAE 30, SAE 40, 10w-50 and 20w-50.

With that said, I'm a fan of using Rotella T6 so far. While at first I thought people were on crack for suggesting it (diesel oil etc.), I think it's what's going to make this engine live to 200k on the original turbo and bearings.

While I could list some casual observations here about the oil, I'm going to do the 1st UOA on my car once it hits 4k.

Just a note on NASIOC: the sticky threads are the best on there, with the most reliable info. Most regular posts usually devolve down to flame wars or 4chan grade trolling.

This is one of the more interesting threads where we argued about this:
http://forums.nasioc.com/forums/showthread.php?t=2140869&highlight=amsoil

If I had to pick another oil, it would be castrol syntec 0w-30.

 

[Thermo1223]

Hey Ed,

I do actually drive the car and apparently it still does after Mobil 1 Advanced Fuel Economy 0w30 and the current fill of syntec and the previous 5w30 conventional oils.

FYI

xw40 not required but not gonna hurt either.

 

[bluesubie]

Originally Posted By: Atticus
Originally Posted By: bluesubie
If the Mobil 1 5w30 is the regular stuff, it will probably show a drop in viscosity to a 20 grade but that's normal for most EC oils in severe conditions. Although we're seeing some good data on the GF5 oils.

-Dennis


This is what i am anticipating, and why I am planning to switch. It looks like GC Gold will hold its viscosity much better hopefully. Going on a road trip this weekend, should be a few weeks before I need to change it again though.


Keep an eye on your oil level during the trip. I would even top off with Mobil 1 15W-50. A guy on nasioc used to get good used oil analysis with three qts of Mobil 1 10w30 and two qts of 15W-50. Most of the time it was a 40 grade, but he managed to shear it to a 30 grade on a couple of occasions.

-Dennis