Tried GC in 4.6L Ford Modular. It felt like...

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Mar 21, 2006
Fredericksburg, VA
...I was towing an ox cart heaped high with elf carcasses. WOW, what a power loss! Water temp was up, and power was down. But I just had to try it.

I took a slower speed 200mi trip with the GC, then drained 5 of the 6 quarts of GC out when I returned. I added 5qts of MC 5W-20 and took the car for a spin. It felt like the engine was on nitrous compared to it having a belly full of GC. But don't worry. The GC is resting safely in a Wal-jug.

The good news is that I really liked the smoothness of the engine with the GC. I have since gone to PP in the crankcase, and it behaves much like a thinner GC so far. Use it.

Thanks to the forum for bringing both GC and PP to my attention. They are exactly what I am looking for in a street motor oil. I will try GC in both the LT1 and 351W next time, and all of the 4-stroke lawn equipment engines!

Originally posted by Old Mustang Guy:
I assume you used PP 5W20.

Actually, my engine is fairly high mileage and was pretty noisy overall with the 1gt GC + 5qt MC 5W-20. The hot viscosity of this mix was 9.5cSt. Stock MC 5W-20 is 9.1cSt at 100C. So I blended up to 10.0cSt with Delo SAE 30 and the engine fell quiet at all RPM. Whew!.

I blended PP to get to 10.0cSt hot viscosity to match my previous best oil mix. I used 2 qts PP 5W-20 and 4qts PP 5W-30. The engine is dead silent, so I will go down toward 9.1cSt next time. Overall engine feel is excellent, but I know there is a little more power to be had by blending down.

You might start at 9.1cSt to match the MC, but PP seems to drive thicker than it is much like GC.
Ahhhh, Rodbuckler (great screen name, btw), you've missed the point entirely. GC is magically green, NOT green magic. Seriously though, you're to be commended for giving it a try. Your result is not unheard of. Some engines clearly aren't at their best on this stuff. Since yours is one of those, move on to something else, leave the dwindling supply of green for those who really want it, and don't bother looking back.
I experienced almost the same thing in my '98 5.4L Expedition. I've always run M1 5W-30 in the summer and 0W-30 in the winter. Last summer, I switched to 6 qts of the green. My mileage went down about 5%, engine response declined (felt sluggish), but felt and sounded smoother. I kept it in for the summer/fall, and switched to M1 0W-30 for the winter. Immediately it felt like I added two more cylinders.

A few weeks ago I switched out my winter mix for 6 more qts of the green and the same thing happened. I will still run it in the summer because I like how it feels and sounds. I might try mixing 3 qts of green with 3 qts of M1 0W-20 next winter.

Originally posted by ekpolk:
Your result is not unheard of. Some engines clearly aren't at their best on this stuff. Since yours is one of those, move on to something else,

Thanks ekpolk.

I knew GC was going to be too thick in my back-spec'd 5W-20 engine, but I just wanted to feel how the engine ran with it. And only one of the quarts was green (the one that JAG missed). I can best describe GC as a thick 30 that drives like a 40.
I respect you guys enough to accept that you experienced what you say you experienced, but I cannot figure this one out. I run GC in a 95 Ford Taurus with a 3.0L Vulcan engine that--bless its heart--didn't have an access of horsepower to begin with and at 6000-7000' regular operating altitude it REALLY is pushing its limits. I saw no degradation in performance when I first started using GC and I would think if ANYONE would, it would be me in this engine. I just cannot figure out what you guys are experiencing. GC is a thick 30W, but it isn't honey...or STP.
The Ford Modular Motors are 5W-20 engines. So GC is pretty far off in the viscosity department. My motor was back-spec'd to 5W-20, and it wasn't for gas mileage reasons. I tried numerous 30's and thin 30's, and they ran poorly compared to what is in the engine at this time.

I will update you on my OCI with PP since I am nearly at 3000 miles with it in the crankcase. I have topped-off with PP 5W-20 to bring the mix in the crankcase to about 9.3cSt at 100C. The thinner I continue to make the oil, the better the engine has run. The engine runs very quietly and smoothly at all RPM, which I find quite satisfying. Power is also notably up at cold start. I am extremely pleased with the Pennzoil Platinum.
Forgive me if this has been answered elsewhere, but i've noticed on the back of Pennzoil Platinum bottles it states as being distributed by Sopus (or something like that). Is PP the same as Shell Helix Ultra? Or is it a unique formulation for the US?
I do believe that I heard that only the PP Euro 5w-40 was Shell Helix Ultra. But the other non-Euro formulations were formulated specifically Pennzoil Platinum.
On another PP note, I would like to know which is better, PP 5w-30, or PP Euro 5w-30.....Any comments? I will probably make another post on this.

Originally posted by Rodbuckler:
...I was towing an ox cart heaped high with elf carcasses. WOW, what a power loss! Water temp was up, and power was down. But I just had to try it.

What motor was this, if you don't mind my asking? I am considering GC into my 4.0 SOHC Explorer. This engine is not back speced for 5W20. Ford has specifically excluded it. But this post is giving me second thoughts about the GC. Thanks
The 5W-20 and 5W-30 PP have a slightly different smell to them. They have a "non-motor oil" smell that is similar to but not as good as GC. The smell of the oil in the engine is also strange. I am surprised how much more buttery smooth the PP runs than the MC at similar hot viscosity.

The engine is a 1996 4.6L Ford Modular Motor in a Mustang GT. I thought I would have pulled the engine by now and given it a 100HP tune-up, but it is running so well that I can't bring myself to do it.
My experience was quite the opposite. I am running PP 5W-30 in my 4.6 2V V8 (00 Crown Vic) and did not experience a smoother running engine. It's about the same as with M1 5W-30 and GC 0W-30. I am running GC 0W-30 in a 5.4 2V V8 without any problems (1 year / 6k mile intervals) and this is the second time it has used GC 0W-30.

The only negative to GC 0W-30 I experienced in my 4.6 2V is that I lost about 1-2 mpg.
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