My experience with GC Green so far

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Dec 22, 2005
New England
1994 Saab 900S 2.3L naturally aspirated with 58k miles. I have noticed that my engine is much quieter and seems to run very smooth. I also had a slight leak before when I was using havoline 5w30 full synthetic and with GC there is no more leak. It completely dryed up and is still dry. I have had the GC in now for only around 500 miles. Overall, the car seems pretty happy with this stuff. Here in Northern Maine the weather is definitely cold. Every morning it's usually around 0F this time of the year. The car turns over really easy and always starts. Those are the good things. Now for the not so good. I have noticed about a 2 mpg drop in my fuel on GC. I hope this gets better but its not enough of a drop to make me not use it.
yup! same what happened to me (GC - gold). My car is a 2004 BMW X3 w/ 10k miles. I have noticed a sudden drop in mpg from 18.5 to 16.0. I just have 1500 miles on the GC and i cannot take it anymore, so decided to try Mobil 1 0w40 and run it up to 7.5K miles, i just changed it yesterday i'll post my observation ASAP. But, in terms of performance all i can say it's okay and its still clear when i drained it. Other synthetic oils w/c i may consider if im not satisfied w/ M1 0w40; Vavoline maxlife 5w30, Valvoline 5w40, Castrol Belgium 5w40 or stick w/ BMW brand 5w30. All this oil is ACEA A3/B3 rated and BMW LL 98-01 approved. I'm planning to do 7500 miles OCI w/ this oil as my alternative w/ my free OCI from the BMW dealership w/c every 15 k miles w/ their BMW brand. Anyone there had there experienced in terms of mpg w/ this said oils? Thanks.... orics
I switched from the BMW 5w-30 high performance sythetic to GC as well. I haven't noticed any MPG difference, but I don't keep track of that sort of thing. The viscosity of GC is almost, if not exactly the same as the BMW stuff at 100 degrees C. I wonder why you'd see a decline in mileage. Could it be winter vs. summer?
MPG is hard to quantify...there are so many variables. No apparent change in my mpg going to GC from Mobil 5000 5-30 nor from Havoline 5-30. IF there is a difference, I haven't detected it, and I check it every tankful. For me to believe there is a difference in any given engine, it would take something like a cruise-control trip out and back of sufficient distance to burn an entire tankful, change the oil and repeat. Of course, fuel (which includes using the SAME pump and the same filling point, etc.), temperature and wind would have to all be the same on the comparative trips. IF this was done a couple of times with one oil, and repeated a couple of times with another oil (both new oils, of course....I wouldn't accept comparing an old oil with 5000 miles on it to brand new oil), I'd accept the statement that there was a difference. Otherwise, it's just a WAG.
A tight, new engine like mine did not respond well to GC. I am tempted to try it again simply bc I'd like to rule out the other possible variables that could have caused this such as type of gas etc. But I'm fairly convinced that a new Honda engine doesn't really benefit from anything over 11 cSt. GC = 12.2 cSt.
jdavis wrote > > I have noticed about a 2 mpg drop in my fuel on > GC. orics wrote> > yup! same what happened to me (GC - gold). My > car is a 2004 BMW X3 w/ 10k miles. I have > noticed a sudden drop in mpg from 18.5 to 16.0. I doubt very much that GC accounted for this change in either case, particularly one that is 13%. See my other posts on this topic. Titan hit on many good items in his comments above and there are many other variables that would have to be eliminated or closely moderated to avoid comparison issues. Regards, Rich
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