Just put GC in my truck

Not open for further replies.
Jun 26, 2003
Columbus Ohio
Well, I changed out the RP 5w30 and put in the GC. I hoped I would be able to tell a difference in the way the engine ran, but I really can't........If I had to say one way or the other, I would say it ran better with RP. As I run RP, I can tell it must be thinning, for over the OCI, my oil pressure drops. 32psi when I start when the RP is fresh, and about 25psi, 3000 miles later. I expected the pressure to increase with GC due to the increased viscosity, but it didn't. I am running 25psi with fresh GC.
Oh well......the RP is going to a lab next week, and I will have the GC analyzed next time I change, and I will let the UOA's speak for themselves.

[ October 24, 2003, 07:40 PM: Message edited by: sbc350gearhead ]
I figured you would have shown at least a small increase in pressure. My truck (with a 4.3L) ran 53 for a high and 25 for the low when the oil was hot (I was using Valvoline Syntec 5W-30 before I discovered this site). Since I changed to GC the hot pressure is 55 and low is usually 27, sometimes its around 30.

Originally posted by sbc350gearhead:
Yes, I was very surprised as well......especially considering the testimony from patman, when he tried it in his camaro.


I saw a more dramatic difference in the sound and smoothness of my wife's Honda when going from RP 10w30 to GC 0w30, so some engines will react differently than others. But she has no oil pressure gauge to compare things that way.

In terms of oil pressure in my Firebird, I do see it being lower on cold starts than it was with Schaeffer 5w30, and slightly higher than Sch 5w30 once warmed up.
My car had slightly better turbo response with Valvoline than the GC.
Plus, the engine was a lot quieter with Valvoline. The 1.8T is naturally a loud engine, but now I can really hear it with GC in it. I'm likely to stick with GC though because it looks like it's pretty shear stable.

Originally posted by sbc350gearhead:
Camaro....Firebird....they're both F-bodies, and sweet cars.

True, but I've always been a Firebird guy, having owned 3 of them:

1995 Trans Am automatic
1998 Firebird Formula 6 speed
1995 Firebird Formula automatic

My father in law always refers to my car as a Camaro, even though he knows it's a Firebird. He does it to bug me!

Originally posted by crashz:

Patman, why did you get rid of the 98 Firebird w/ that sweeeeet 6 speed? I bet that car was a rocket!

It certainly was! With just a few relatively easy mods, it went 12.68 at 110.6mph!

I traded it for a 97 Grand Prix GTP, for a number of reasons which seemed good at the time, but very soon after I regretted it, and less than a year later I traded the GTP for my 95 Formula. I wish I could've afforded to get another 98, but they are too pricey and even if I did have the money, they are too hard to find also (they only made 2100 Formulas in 1998)

Getting rid of that 98 Formula was the biggest regret of my life, something I think about all the time.

Here's a nice picture of it:


(the color was Blue Green Chameleon, one of only 124 made that year)

[ October 27, 2003, 02:10 PM: Message edited by: Patman ]

VeeDubb, that was with Valv. SynPower 5-40 right?

I remember pretty sure he used that V VV approved oil as I used it too a few times myself, before the GC craze.

[ October 27, 2003, 10:16 PM: Message edited by: TSoA ]
Not open for further replies.