K so RRM says we 4g94's gotta use 20w50 CONVENTIONAL. I am not gonna argue there recommendation but I looked everywhere for it and I can't seem to find it... So I was lookin at walmart and found "Castrol GTX 20w50" which i believe is a synthetic blend.... Has anyone had any experience using this on a turbo 4g94? Jus tryin to do some research.. oh and by the way the only other choice I found is "Chevron 20w50"(dunno if it's synthetic or whatnot) I hope somebody has some knowledge about this... PAGING ROCK..... thanks in advance

 

I think others had problems using synthetic because
the oil was so thin that the oil pump did not operate properly

 

i use mobil 1 fully synthetic for my turbo kit and i use 10w20


EDIT----

um..my girl is confusing me is it 10w30?? darn i'm getting frustrated

 

all i can say is get an oil pressure gauge and compare between synthetic, conventional and blend.

 

Castrol GTX isn't synthetic. I work at autozone and we sell about 5 different brands that have 20w50. I don't think anyone sells 20w50 in synthetic. The bottle will say "fully synthetic" or "synthetic blend" if it is.

 

hmmmmm^^ interesting. So castrol GTX is conventional?? I could've sworn I heard them say something about comparing GTX to conventional in that commercial with the two chargers on the dyno's

 

There is a synthetic castrol, but not in 20w50. At least not at any regular auto parts store. Synthetic is usually sold in the 5-10w20-40, the common oils (and the diesel as well). You just have to look at the bottle

 

it doesnt say on the bottle synthetic so am I safe to assume its conventional?

 

When I switched from 20w50 non-synthetic to Lucas Racing 20w50 I saw a 3-5psi drop in oil pressure after. My oil pressure does not drop any lower than 15psi and that's after a hard run at 10psi.

 

^ that is the kind of info we need. Lucas is full synthetic and compared with a conventional the difference in pressure is only ~5 psi. Interesting... And you haven't had any problems with the synthetic either huh?....

 

Nope. Before I was turbo'd I ran Lucas 5w30 from day one. After going turbo I used conventional 20w50 for the first 5,000 miles. I've been using Lucas 20w50 for about 35,000 miles now and not a single problem. I do believe that anyone switching their oil should monitor the pressure via a gauge. Definitely a must with a turbo.

 

ya i got a oil press gauge ready... so what pressure you recommend at idle and at various rpms then? Cuz i see about 12ish non-turbo

 

According to the Mitsu service manual, oil pressure at idle should be above 4.2psi. At 3500rpm, 43-100psi is within spec. So the tolerances are pretty loose. I'm actually thinking of switching to a 10w30 to run something thinner and free up some horsepower as long as I can maintain adequate pressure.

 

perfect. this is exactly what I was looking for. Figure that as long as the pressure stays within range you can pretty much run any type of oil... be it synthetic or conventional. Won't get into the argument. Senate, you got any pictures of how you mounted your oil press sender? Read the threads bout you having problems with the brass ones and switching over to some stainless peices.... just curious cuz I have mines connected to the hex bolt over the oil filter using a nylon tubing kit from autometer to mount it off the engine....

 

I used a steel 1/8" NPT tee fitting in the location of the stock oil pressure sender. DO NOT USE BRASS FITTINGS! DO NOT USE ALUMINUM FITTINGS! I have used both in the past and have broke both within hours. It's gotta be steel or stainless steel fittings.