GC Gold costing me pure $GOLD$

[fred0803]

quote:

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Originally posted by 427Z06:
It's funny to see people exclaim that manufacturers went to 5w20s simply for better fuel economy. And in the very next breath they exclaim GC, almost a 40 grade, produces no reduction in fuel economy.

I've seen a 4% drop in two engines, V6 and I4 (spec's 5w20), and it was too close to call in a large V8 (spec's 5w30) due to lack of data. This is in Texas summer heat too.

4% x 25 mpg = 1 mpg.

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Number 4.....
Don't be a putz.
GC has given me at least if not more than Mobil 1 5/30 milage wise. If it wasn't true I wouldn't be saying it. As far as the 20 weight debate, don't include that here. That isn't related as well. And I have never said as others have done the same, that, 5/20 was put in soley for milage reasons by Ford, Toyota and others. Not true.
I continue to use GC because it's a great oil and gives me equal if not better milage than Mobil 1. and people saying they are taking a 10% hit is bull. One mile per gallon is totally insignificant. Get over it. Maybe the Summer heat evaporated 1% of the fuel...

 

[fred0803]

Oh putz, I didn't see the first time that you were comparing 5/20 to GC. Now that may account for some of the 1MPG don't you think???

Geech,
And why are you putting as you stated "an almost 40 weight oil" in your cars spec'd for 20 weight. The question isn't GC now it becomes why the H are you doing that. And if so, why Bioch about 1 MPG. Me think you complain about a lot more than MPG in life.

 

[427Z06]

quote:

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Originally posted by fred0803:
Don't be a putz.

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The feeling is mutual...I'm sure.

 

[OriginHacker21]

My vehicle: 2.2L Ecotec 140HP 2004 Pontiac Sunfire

Work: 220 miles/day (110 miles one way).

Going from Mobil 1 5w30 to GC 0w30 - Increase of 2-3 MPG. After using GC 0w30 for 30,000+ miles and better driving habits - I'm 6MPG above what I used to get.


I have a scanguage and spend a lot of time watching/recording the MPG. In all honesty - there are a billion different factors resulting in your MPG increase/decrease. **I've NEVER had the same MPG as I did the day before.** Someone pulls in front of you - you slam on the brakes. Results in a waste of gas as you get up to speed again. Wind - hardly noticable with windows up - can be hurting your MPG - tires (My tires are constantly changing their PSI every 2-3 weeks), etc... Just too many variables in my opinion.

May have a lot to do with the engine... I know several people IRL with 4cyls Hondas/Toyotas that were told to put in 10w40 in their engines. Fuel mileage went down. I'd put a 5w20 in a vehicle that calls for it. Still, IMHO - 1MPG is hardly anything

.

I've driven 30,000+ miles since February and I'm still finding little ways that I can learn to drive better to save more gas.

When I started driving I averaged 29-30MPG. Now I'm averaging 36-40MPG. Driving habits are everything.

 

[427Z06]

If you see increased MPG with a more viscous oil in a modern rollerized valvetrain engine, it indicates it's not sealing well at the piston/ring/cylinder interface. That could be the key here. Slop engines are recording higher MPGs with more viscous oil, tight engines see a decrease in MPGs with more viscous oils.

 

[avette]

quote:

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Originally posted by OriginHacker21:
My vehicle: 2.2L Ecotec 140HP 2004 Pontiac Sunfire

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OriginHacker, your 2 year old Ecotec must be a complete junker. (sarcasm)

So it seems the GC forum is finally coming under the attack of the thinner=better crowd.
Get ready to get banned for resisting the "inevitable".

 

[427Z06]

quote:

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Originally posted by avette:
So it seems the GC forum is finally coming under the attack of the thinner=better crowd.

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Oh such repartee from a neophyte no less.

 

[TooSlick]

All things being equal, fuel efficiency under steady state conditions is inversely related to lubricant viscosity - or more specifically high temp, high shear rate viscosity. This assumes a fairly new engine in good condition and without excessive ring/cylinder wear.

Fuel efficiency evaluations of lubricants are carried out under carefully controlled conditions with engines running on test stands. There is no doubt that viscous losses in the bearings and at the ring/cylinder interface are reduced with low viscosity lubricants. It is entirely consistent with well established principles of fluid mechanics and is NOT open to debate.

TS

 

[avette]

The debate is by how much.
And it's clearly not by 10%.
Please note the name of this thread.

 

[427Z06]

Let's look at some viscometrics:

code:

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T(C) Syntec 5w30 * GC 0W30

-20° 2079 2609

-10° 889 1127

0° 429 547

10° 229 292

20° 132 169

30° 82 104

40° 54.0 68.4

50° 37.3 47.0

60° 26.8 33.7

70° 20.0 25.0

80° 15.3 19.1

90° 12.1 15.0

100° 9.7 12.0

HTHS 2.9 3.6

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GC is 27% more viscous than Syntec 5w30. Has a HTHS 24% greater. And we're not even considering FMs.

Let's say that this change in viscosity effects parasitic losses by 2% relative to rated horsepower. Now, no one drives around at WOT all the time. You might be using 10% of rated horsepower to run down the road at highway speeds. Since the parasitic losses don't generally decrease anywheres near as much, those parasitic losses may represent 20% of the power being produced. So in this case we're looking at a 5% increase in parasitic losses when driving down the highway. Moving to a 5w20 would make that 8%.

 

[avette]

According to Ford:
"Using 5W-20 oil can increase fuel economy by about 6/10ths of a percent compared to 5W-30 and more if you are currently using a higher viscosity oil."

 

[427Z06]

quote:

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Originally posted by avette:
According to Ford:
"Using 5W-20 oil can increase fuel economy by about 6/10ths of a percent compared to 5W-30 and more if you are currently using a higher viscosity oil."

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Compared to a friction modified GF-3/GF-4 5w30 oil.

And let's not forget the

quote:

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"...and more..."

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part.

 

[TooSlick]

427ZO6,

Quit confusing folks with the facts....

TS

 

[avette]

I just posted a factual figure supplied by Ford and based on its internal testing.
Where are your facts? I'm confused...

 

[427Z06]

avette, I've posted many facts in a lot of threads on various subjects. I'm too lazy to repost all of them just for you.

I'll end my posts to this thread with this one last point. Go easy on the guys who see a decrease in the fuel economy when they move from an oil with a HTHS 2.6-3.0 cP to one with a HTHS of 3.5 cP. Virtually all the research I've seen is on their side.

 

[avette]

Cool