GC in my '06 Honda/Acura: Update

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Feb 1, 2006
I know, I placed a post in the General Automotive section already, but anyone browsing here for GC info should read this. I am VERY pleased with it. My '06 RSX Base 5-M has 12k and I decided to go w/GC on a whim....I was going Mobil 1 0w-30 but figured it's still summer and figured, why not try it? The engine is 100% happy, it's obviously smoother and quieter but revs not easier, but nicer, so I can drive it in the powerband. Overall, it's a decent trade-off. Now I can feel good about the long Honda (10k) intervals, get good protection when I rev/hammer it. The overall experience is BETTER. I am doing 3 OC a year, every 4 months starting for Dec, but will still use M1 0w-30 for winter. I have both oils here and probally in this car the GC would not run out well in the cold, but for now it's great. I will do the 2 other OCs with it, probally 10k in 4 months for me. The only question mark is mpg, but I am not thinking there will be problem. Anyway, I tried 12cSt Delo 30 in it for a few days and definately did not like it as much. Now it is like...more "solid" and silky. Although I am aware of warming-up, it is not an issue like the Delo was. I am happy and re-arranged my oil stash accordingly.

PS I think people who have tried this combo mistook quieter for less power. I do not think that's the case.
I tried GC for a couple of OCIs in my Honda V6 a couple of summers ago. Although it was smooth while hot, it still produced a 4% fuel mileage hit and felt especially sluggish during warm up. When I switched back to 5w20, it felt like I unleashed another 10hp. Mind you I was enamored with GC then, like many are today, and was wishing, hoping, praying and almost got myself believing it was better, but at the end of the experiment I had to be honest with myself and admit it wasn't worth the mileage and performance hit.

I now use GC only in applications that truly benefit from it's properties.

Good luck with your experiment.
It's seeming ok. First 1/2 tank mpg was right on the money, 29.75 hwy, average-average.

I am trying not to drive hard like I now WANT to drive, so I can get a nice high-end mpg reading and then go from there. I have to admit, I have a BIG GC stash that has to go ~somewhere~ and I do like the way it's driving. The EXPERIENCE of driving with a somewhat heavier (and smoother) oil is one of the few points NOT hammered to death on the recent 5w-20 verses Reality threads.

With the Oil Plan I have now, between my wife's CRV getting M1/GC and my car getting M1/GC/GC, I have 3 years of changes....so I might as well quit BitOG, right?

BTW, 427Z06, I take all long trips, which is a plus. Also, I sorta think the GC makes US WANT to hammer the car more, which could acct for the mpg. Likely, only a dedicated hyw cruiser would know the real mpg results.
We run Motul 8100 0w40 in our Odyssey V6, and get 22.8 MPG in mixed driving with the AC on ALL the time. GC is the winter mix, similar MPG.

Has anyone dynoed a Honda engine before and after GC, or 0-60 runs?
I think you would have to get a plot of hp/rpm to know the story. I feel like I get more power some spots and lesss at others. Good power at mid-rpm and maybe a bit less before you hit high revs, where is comes on strong. The "bit less" power area is where it's much smoother than with lighter oils, so a decent trade-off.
The "pumping losses" associated with a thicker oil increase at high rpms. So using a 3.5 Cp (HT/HS viscosity) 30wt oil, vs a 2.7 Cp, xw-20 will make a difference in something like a Honda. If you had a pushrod V-8 that cruised @ 2000 rpms, it would hardly be noticable.

My 2.0 RSX has 7K on GC. Runs smooth and oil looks great but its sluggish. Felt much more rev happy with 5w-20 or M1 5w-30. Only complaint with M1 was engine noise. I'll try PP 5w-20 after my 10K run on GC.

Originally posted by Auto-Union:
BTW, 427Z06, I take all long trips, which is a plus. Also, I sorta think the GC makes US WANT to hammer the car more, which could acct for the mpg. Likely, only a dedicated hyw cruiser would know the real mpg results.

Virtually all of my trips were long too...and during the hot half of a central Texas climate. 95% of my commutes were 60-138 miles at the time, and since they were work commutes in the rural part of Texas, they were highly consistent. Repeatable use of the cruise control on the same sections of highways along with repeatable use of WOT on on-ramps and back roads. Believe me when I tell you I wanted to see no difference in economy since I was enamored with GC just like many people. But in the end, when I tallied the numbers I had to be honest with myself.

And as TooSlick predicted, I don't see the same difference in large pushrod V8s.
Steelers, do you have a Type-S? I assume not since you are indicating a 20 weight. Anyway, I'm coming off of Havoline Synthetic 5w-30 and Havoline 5w-20.
Hey Auto-Union...if you like the feel and don't mind the mileage and performance hit, keep on truckin'. It won't hurt anything. GC is great oil.
I've put GC in my 05 Accord and it clearly made the engien sluggish. I'm a huge fan of GC, it's just not the most ideal oil for my car.
Well, I refilled after 1/2 tank on the GC to get a clean reading on mpg. Then I took my normal trip to Phila and returned..ta da, I got 1 mpg MORE than I expected! Usually for that run, I get about 30.5 mpg. I got 31.5, not bad. I figured as long as I stayed above 30, I would be ok, did not expect to exceed previous readings. Ok, I admit it's just one tank, but it's looking good. At the 1/2 tank mark I was over 230mi, usually I barely make 200mi, so there is something going on that is not at all bad. Still like the way it runs and I re-computed my OCI out to 4 months, 10k. I am totally pleased, no issues at all. I'll chime back in if anything changes.
If GC had mileage improvement potential, it would be fully certified GF-3 or GF-4. Otherwise, any mileage gains observed is most likely due to the placebo effect.

Originally posted by burnout:
Not sure if this helps, but I dynoed my 3.5L honda V6 on GC (advertised 250hp) and got 217FWHP.

A drop of 33 hp? Yikes! Did you dyno the engine with the recommended 5w-20? Are you sure that this drop in horsepower is completely attributable to the oil?
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