Castrol GTX 20-50 in Harley Evo

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If you are going to use a car 20w50 in a Harley, Valvoline VR1 and Kendally GT1 both gave stellar results in a UOA on here in a harley big twin.

Castrol GTX is just not the product it used to be in my honest opinion. BP really cheapened the brand. They are notorious for having a reputation in cutting corners/costs to maximize profits. Only Castrol products I still use are German Castrol 0w30 and their Transmax ATF.
 
Originally Posted By: Robenstein
If you are going to use a car 20w50 in a Harley, Valvoline VR1 and Kendally GT1 both gave stellar results in a UOA on here in a harley big twin.

Castrol GTX is just not the product it used to be in my honest opinion. BP really cheapened the brand. They are notorious for having a reputation in cutting corners/costs to maximize profits. Only Castrol products I still use are German Castrol 0w30 and their Transmax ATF.


Would you have a UOA to show the problems with the GTX.

eddie
 
If your not using Harley's brand of oil, the manual says to us a SG rated car oil. As long as the Castrol car oil has the SG rating on the bottle, you'll be fine. Evo's aren't that picky.,,
 
Originally Posted By: EddieCairns
Originally Posted By: Robenstein
If you are going to use a car 20w50 in a Harley, Valvoline VR1 and Kendally GT1 both gave stellar results in a UOA on here in a harley big twin.

Castrol GTX is just not the product it used to be in my honest opinion. BP really cheapened the brand. They are notorious for having a reputation in cutting corners/costs to maximize profits. Only Castrol products I still use are German Castrol 0w30 and their Transmax ATF.


Would you have a UOA to show the problems with the GTX.

eddie


I never said it would be a problem, just that there are better and proven options available at similar costs. I know in the days of SJ and SL rated PCMO's that people did often use GTX and their bikes survived. But I have also seen what castrol's dino motorcycle oil is like on here and the general consensus is it was garbage.
 
I ran gtx in my wifes Toyota, you definitely want short oci's cause it will plaque a motor. I just don't understand all the hype with GTX people have had over it..

The motorcycle stuff, Ive not seen any issue, course its usually out of there by about 2500 miles.
 
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Originally Posted By: BigCahuna
If your not using Harley's brand of oil, the manual says to us a SG rated car oil. As long as the Castrol car oil has the SG rating on the bottle, you'll be fine. Evo's aren't that picky.,,


SF and SG are obsolete auto standards and had no motorcycle specific reference to start
with... All specifications prior to SL are now obsolete and although suitable for some
older vehicles are more than 10 years old they do not provide the same level of
performance or protection as the more up to date SL and SM specifications.

The American Petroleum Institute (API) sets minimum for performance
standards for lubricants... it is split (for passenger cars) into two
catagories. S = Petrol and C = Diesel, most oils carry both petrol (S)
and diesel © specifications.

The following table shows the API specifications behind the letters...
is your oil up to date???

SG - Introduced 1989 has much more active dispersant to combat black
sludge.

SH - Introduced 1993 has same engine tests as SG, but includes
phosphorus limit 0.12%, together with control of foam, volatility and
shear stability.

SJ - Introduced 1996 has the same engine tests as SG/SH, but
phosphorus limit 0.10% together with variation on volatility limits

SL - Introduced 2001, all new engine tests reflective of modern engine
designs meeting current emissions standards

SM - Introduced November 2004, improved oxidation resistance, deposit
protection and wear protection, also better low temperature
performance over the life of the oil compared to previous categories.
 
Larry -

Most of us know that.

Funny though - because I was wandering around a bike shop and looked at some of the "Genuine" brand oils (Honda, Yamaha, etc.) and they had "SG" on the bottle. One had it in big letters, right on the front.

I wonder if this is because the vast majority of the metric motorcycle owner's manuals state "SG" or higher.

Of course, the Genuine Harley-Davidson oil gives no clue as to the API certifications, if any.
 
Funny how alot of mfgrs state the old SG spec for their bikes. So it would appear that any oil made after that spec was changed, would be acceptable to any mfgr. I've stated many times that I've never seen an API symbol on a bottle of "motorcycle specific oil". If Honda's oil has it, it must be car oil that they also say to use in their bikes. Most mc specfic oils say they meet a given spec, but don't actually test it to see if is.,,,
 
The problem with some of the newer oils is the phosphorus limits affect ZDDP anti wear additives. I know that many people ran lobes off flat tappet cams in cars using newer oils because they did not have the proper anti wear additive package.

The reason I mentioned Kendall GT1 and Valvoline VR1 is because they have boosted zddp and have shown great wear numbers in harley v twins.
 
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My buddy runs VR1 50, or M1 15-50 in his '07 Road glide with no issues. I also have a client who runs Redline 10-60 in his Harley and he swears it is the best oil he has ever used in his bike. He says that it runs the quietest, and consumes the least of any oil he has ever tried; and he tours regularly.
 
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I just changed the oil in my 2007 Twin Cam using 20W-50 Castrol M/C oil. It a little over $18 for 3 quarts at O'Reilley's. I only have a couple hundred miles on the oil, but so far the engine is nice and quiet.
 
Is this the dino Castrol 4T?

The general consensus on that oil is that it is not very good at all. I know when I got my first V twin in 2007 that my Yamaha HATED it. But that was a shared sump engine so the shifting was terrible and the clutch feel was poor.
 
On my VFR I ran Castrol 4t just before running redline, it work as well IMO. Im on Valvoline 10w40 right now which has been very usuable, I probably bounce back to Castrol 4t, when I dump the Valvoline in the nest couple weeks.

But the last 4 oils, Castrol, redline, Valvoline and supertech 15w40, the only one I really didn't care for was the super tech, I rate it about like the rotella 15w40.
 
Originally Posted By: Bobaloo22
Anyone tried this in their Harley? I tried to do a search but could not find anything.

Thanks,

Bob


According to my dad Castrol 20w50 is the current fill in one of his HD's (96 Sportster 1200). He said it's been in it since Spring 2013 but it only has maybe 1300 miles on it. This is a secondary bike, doesn't see much road time. He said he'll run til next summer and change reguardless of mileage. I guess he was given this oil by a friend and decided to try it in the Sporty. Can't tell any difference between the Castrol and the M1 15w50 which he usually uses in his HD's.
 
Being able to differentiate oils seat of the pants is special gift. I know shift feel and all.Back in the 70's,80's Castrol was it for bikes. Rotella T is well regarded and proven why experiment.
 
Thanks everyone, I was just curious. I've used VR1 and Mobil 1 for years and like them both. Got a jug of the GTX dino and wondered if it was as good as it used to be. In the late 70s and 80s I ran it in my Hondas with no problems. I'll keep it to use for "topping off" after an oil change. Actually my buddy runs M1 (2 qts) and VR1 (1 qt) in his Harley and said he couldn't be happier. So I may try that next time.

Bob
 
Originally Posted By: Robenstein
Is this the dino Castrol 4T?

The general consensus on that oil is that it is not very good at all. I know when I got my first V twin in 2007 that my Yamaha HATED it. But that was a shared sump engine so the shifting was terrible and the clutch feel was poor.


I agree. I remember seeing UOA's where that oil sheared right away to near 30 weight.
 
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