best oil to use??

[lacroixdp]

You don't want 5 weight in a turbo motor-oil's too thin for our bearing clearances...unless you live in either Alaska or down on Antarctica.

You're absolutely correct in that Mitsubishi recommends that viscosity, however 5 weight is just fine, even in the summer time. This motor has been using 5 weight for years and the bearings look like brand new on visual inspection - you can verify this on the analysis shown below. The 5 weight makes absolutely no difference - it's the latter weight rating that counts once the motor is warmed up. This was taken with a blown head gasket, right before the engine got yanked. As you can see, bearing wear is perfect, and all this motor has ever seen is 5w30, even in 100+ degree weather.

 

[604CruisinCroat]

Royal Purple is superior to Amsoil.

There is a study out there....I can't find it but I read it a few months ago.

The ones that came out on top were Pentrite, Royal Purple and Valvoline Durablend believe it or not.

 

[donniekak]

I just rebuilt my engine, the rod bearings were fairly tight, .001", while the main bearings were a little loose, about .003". Right now I've been running cheap TropArtic 10W-30 for the break in, what do you recommend I run in the Summer time and Winter time? I was going to run 15W-40 dinosaur oil during the summer, that I get for $7 something a gallon from a local oil distributor but I've been thinking I should start running synthetic after the first 1500 miles. Also who has some of the best prices for oil?

Wow, with that much difference you will need to comprimise. On a tight (.001"-.0015") engine 30w is about as thick as i go because with a thick oil at that clerance you get to much heat in the journal because of the slow flow. I build alot of 4g63's and 6g72's for higher power and try to go about .0025"-.003"with them and run 40w. with your setup i would probably try a few different 30w, and 40w oils until i found one with the oil pressure i like to see. I have a motor on the stand right now that is at .0013"rods, and .0015" mains. It will see 30w non detergent generic oil for 3 changes (500 miles), then a good 30w synthetic.

 

[92 GSR-4]

I have over 50K on my rebuild, and used 10W-30 Cheapo for the rebuild. After 500 miles I switched to Mobil 10w-30 Full Synthetic and have never had any problems. This is on a motor that has been ran hard all 50K+, and has had 185 compression across all cylinders (even today, I tested today!). On top of that. I have an inline FP filter going to the BB turbo that has never seen a fleck of metal.

As long as you change your oil when its due...it doesnt matter.

A friend of mine had a 220K motor that ran 12.40's, he used cheapo motor oil in it all the time, but used engine flush every other time. At 220K he pulled bearings and measured. They were all still within spec.

Your concern is to change your oil more than what brand you use.

 

[Defiant]

ive done a search and found nothing.

Really.

http://www.dsmtuners.com/forums/fre...questions/280920-oil-should-i-use-filter.html