TheSamba.com :: View topic - What oil are you running in you Subaru conversion?

Wed Oct 17, 2012 3:57 am

We've got a 2010 2.5l Forester engine in our van. Smallcar spec'd Chevron Delo 15w40 motor oil on their conversion spec sheet.

However, I subsequently read somewhere that engines with overhead cams don't love oils that heavy. So I'm wondering what other conversion owners—particularly ones around the coastal Pacific North West—are running for oil, and why?

Wed Oct 17, 2012 4:07 am

Why not call the local Subaru dealership?

Wed Oct 17, 2012 4:13 am

Full Synthetic 5-30W in my 99 2.5L. You can't beat synthetic for it's superior lube qualities. Higher cost can be offset by longer change intervals. There have been a couple articles on how newer engines run so clean that frequent oil changes are no longer necessary. Subaru recommends 7500 mile intervals on our 2012 Outback.

I have run full synthetic oil in my 03 Jetta with 1.8T. Oil analysis said under my driving habits/conditions 10,000 change intervals were OK. So far I'm at 160K with that engine (all original) . It purrs like a kitten and uses no oil between changes.

Wed Oct 17, 2012 4:43 am

Per Suby - turbo engines MUST use synthetic. Non turbo can use dyno oil, but why not go the extra protection. I run 5W-30 synthetic in my 07 WRX.

Wed Oct 17, 2012 5:43 am

5w30

0w40

Wed Oct 17, 2012 6:51 am

Have several 2.5L convers ranging in years 2001 to 2003 (SOHC) and I run full synth 10W-30.

Usually will change after 6k but on occasional super longer road trips will comfortably go longer like into the 7-8 k's.

Always change the filter with the oil.

So far so good and the local flaps seems to always have it on sale along with a free filter (although I tend to use mostly Subie filters).

If I lived in a Siberian or Saharan climate I'd have to rethink it.

Wed Oct 17, 2012 8:06 am

Mobil 1 10/30 with Wix filter @3,000 mi

Wed Oct 17, 2012 8:20 am

I used 10W30 in my 2000 2.5 litre engine swap for the first 30,000 miles but after reading the manual have switched to 15W40 Rotella T.

The Subaru manual calls for for regular use but 15W40 if you're towing a trailer with your Legacy Wagon. I figure that pushing the van is more work than towing a little trailer, so... The engine sounds much happier.

I'm also using a Wix/NAPA filter for an Isuzu - #15344. It fits very well and gives me a little more capacity - a little more than half a pint. Its not a remote cooler but its nice to have a little more oil capacity.

Wed Oct 17, 2012 10:58 am

5W-40 full synthetic.

Wed Oct 17, 2012 11:08 am

10-30 synthetic per the owners manual for my ej22. 5-30 is also listed but not for hard driving which i think a vanagon is considered to be do to the weight.

Wed Oct 17, 2012 11:09 am

Glenn wrote: Why not call the local Subaru dealership?

Seriously.

Wed Oct 17, 2012 12:04 pm

Mobil 1 synthetic 10W-30 with a Wix filter.
That's what was recommended by the expert who did my conversion, which is good enough for me.

(Tip: a large jug is often available at Costco for way less than the FLAPS.)

Wed Oct 17, 2012 1:04 pm

Jake de Villiers wrote:
I'm also using a Wix/NAPA filter for an Isuzu - #15344.

you sure that is not 51334?

Wed Oct 17, 2012 1:19 pm

Franklinstower wrote: Jake de Villiers wrote:
I'm also using a Wix/NAPA filter for an Isuzu - #15344.

you sure that is not 51334?

Yup: http://www.wixfilters.com/Lookup/PartDetails.aspx?Part=51344

51334 is the teeny Subaru filter: http://www.wixfilters.com/Lookup/PartDetails.aspx?Part=51334

51344 is an inch taller. pi x r squared etcetera

Wed Oct 17, 2012 1:51 pm

Jake de Villiers wrote: Franklinstower wrote: Jake de Villiers wrote:
I'm also using a Wix/NAPA filter for an Isuzu - #15344.

you sure that is not 51334?

Yup: http://www.wixfilters.com/Lookup/PartDetails.aspx?Part=51344

51334 is the teeny Subaru filter: http://www.wixfilters.com/Lookup/PartDetails.aspx?Part=51334

51344 is an inch taller. pi x r squared etcetera

Okay, got it - you had 15344 not 51344

Wed Oct 17, 2012 2:20 pm

timichango wrote: We've got a 2010 2.5l Forester engine in our van. Smallcar spec'd Chevron Delo 15w40 motor oil on their conversion spec sheet.

However, I subsequently read somewhere that engines with overhead cams don't love oils that heavy. So I'm wondering what other conversion owners—particularly ones around the coastal Pacific North West—are running for oil, and why? ..I hope you did get in touch with a subaru dealer..somewhere in that time subaru specs a 5w/20 or 30 for that motor..all the more important for the proper subi spec'ed grade of oil if your motor is VVT and even more important again if it has a timing chain...I would give SC a call and ask them to explain why a thick diesel designed oil was recommended, especially an oil with a very low viscosity index of 130+ which is ok for the very large capacity oil fill of a tracker trailer,..but not fit to be used in a gas engine..maybe they made a mistake since they also install diesel conversions..but then again this is not an oil subaru specs for their diesel...anyway subaru would never recommend a "non-starburst" oil for any gas engine..I think in your case the 5w/30 is the spec'ed oil so therefore the subi oil would suffice or you could do better going to synthetic..for example..5/30 penzoil platinum with a viscosity index of 177 or as recommended earlier a 0w/40 ...mobil1 has a VI of 185..both are easily purchased off the shelf and with VI numbers like that you would have no problem of the oil shearing from any high heat situations, which I doubt you will encounter..personally myself, I have been using a 20w oil with a still higher VI for a long time now with no problems..sort of an experiment..but thats me..

Wed Oct 17, 2012 5:21 pm

On all the conversions I've done, I fill them with Mobil 5w30 dino oil and a 6 cylinder Mann filter, nobody has had any problems. I use 2006+ EJ25 engines and that's the oil that Subaru recommends. I use the 6 cylinder filter just because it has more capacity and it fits the 4 cylinder motors just fine. Other engine carriers may have interference though.

I tell my customers that if they're driving it hard, to run 5w30 or 10w30 synthetic. If you're really pushing it in high temps I suppose a 15w40 would be okay, but 5w40 synthetic would probably be better. I wouldn't run a 40 weight in the winter.

Also, the oils intended for high mileage engines seem to work well to prevent the external oil leaks.

In my own van (2001 EJ25) I run Mobil 1 high mileage 5w30 and I change it in the spring and fall regardless of mileage.

If you're running a turbo motor of any make, synthetics are pretty much mandatory.

Wed Oct 17, 2012 7:16 pm

Mobil One 0W-30.

After years of using all the wrong oils, I finally learned the correct way to determine the proper motor oil grade for my engine:

http://www.bobistheoilguy.com/motor-oil-101/

Wed Oct 17, 2012 9:00 pm

Funny, all late engine have a big "5W30" written on the oil filler neck - cap (click on picture for a bigger size):

I wonder why? Maybe it's a "tolerance" thing... :-)

Seriously, I have tested different oil grade just to see lower oil pressure with both, higher and lower grade.

Thu Oct 18, 2012 1:52 am

Thanks for all the info.

Yup—my curiosity stems from the discord between what Smallcar is specifying, and what's stamped on the oil cap. The car we sold in order to buy a Vanagon, and ironically, put the same engine into it, was an '07 forester (the van's engine is a 2010). So I'm used to what the forester used to take.

Trying to understand the different spec, I reckoned that:

• the van's heavier, ergo more strain on the engine, and maybe that was behind the differing recommendation from SC?

• A bit of googling about oil (gah.. what a rabbit hole that is) turns up suggestions that Subaru (and other manuf.) spec lighter engine oils in order to be able to print better fuel economy numbers, at the expense of longevity. Ergo, my layman's interpretation is that maybe SC specs heavier oil to bias towards better wear & tear, rather than better fuel economy? Is this a valid conclusion?

• Sounds like the general consensus here is to go with a 5w30 or 0w30 synthetic instead of the delo. the temperature around here is starting to drop somewhat, and I'm wondering how time-critical moving over to a lighter oil than the 15w40 is? We're about 1000-2000kms away from our next sched. oil change interval...