Pontiac GTO Forum banner

1 - 20 of 29 Posts

·
Registered
Joined
·
228 Posts
Discussion Starter #1
Which is better? Does anyone here use Royal Purple?
 

·
Registered
Joined
·
255 Posts
I use RP in my race car and Mobile 1 in my Goat... Don't notice any difference but the price!
 

·
Registered
Joined
·
910 Posts
Both are just about the same. I used RP and Mobil 1 in my race car also. No noticeable difference. I use Mobil 1 in the Goat just in case there are any engine problems. This way dealer doesn't have a crutch to lean on and deny any warranty claims.
 

·
Registered
Joined
·
410 Posts
If you use Mobile 1, make sure its 0W-40. I've read Mobile 1 thins out over time to be a 30W oil equivalent. I've used them both but went back to Mobile 1 so I had one less brand of oil in the garage (I've got 6 cars). Its a bit easier to find when you need more.
 

·
Registered
Joined
·
304 Posts
Mobile 1 only.........used it for years. Official oil for NASCAR.....

JET
 

·
Registered
Joined
·
454 Posts
Xman said:
If you use Mobile 1, make sure its 0W-40. I've read Mobile 1 thins out over time to be a 30W oil equivalent. I've used them both but went back to Mobile 1 so I had one less brand of oil in the garage (I've got 6 cars). Its a bit easier to find when you need more.

where did you read this?
 

·
Registered
Joined
·
2,100 Posts
Mobil 1 in the engine -- RP and other syns in the transmission, rearend and brakes. I change it every 6K -- and the stuff's still gold in color. Amazing stuff.
 

·
Registered
Joined
·
228 Posts
Discussion Starter #11
b_a_betterperson said:
Mobil 1 in the engine -- RP and other syns in the transmission, rearend and brakes. I change it every 6K -- and the stuff's still gold in color. Amazing stuff.
I thought it was purple :rolleyes:
 

·
Registered
Joined
·
228 Posts
Discussion Starter #12
Maybe that will rid my rearend whine. Unfortunately, I doubt it will get rid of the whine coming from the passenger seat. :D
 

·
Registered
Joined
·
746 Posts
HoldenGTO said:
Maybe that will rid my rearend whine. Unfortunately, I doubt it will get rid of the whine coming from the passenger seat. :D
I haven't tried it in my rearend yet, just my tranny. Seems to shift smoother and makes less noise when I shift. Just remember the tranny takes 4.6 quarts.
 

·
Registered
Joined
·
3,445 Posts
b_a_betterperson said:
Mobil 1 in the engine -- RP and other syns in the transmission, rearend and brakes. I change it every 6K -- and the stuff's still gold in color. Amazing stuff.

Same thing here.:cheers
 

·
Registered
Joined
·
304 Posts
JMM said:
JET.....maybe you should try Mobil1.
Did I miss something?:rolleyes: :rolleyes:


JET
 

·
Registered
Joined
·
364 Posts
For those looking for a fairly good head to head comparison between Mobil 1 and Royal Purple, take a look at this recent independent lab test AMSOIL commissioned on most of the major motorcycle oils on the market:
AMSOIL Motorcycle Oil “White Paper” (1 MB pdf file)

Mobil 1 clearly outperformed Royal Purple in this test, as it does in most of the used oil analysis reports I've seen on the oil forums. For those that don't want do download and review that 1MB file, in the 40 weight category, Mobil 1 ranked 3 of 11 and Royal Purple ranked 7 of 11. In the 50 weight category, Mobil 1 ranked 2 of 15 and Royal Purple ranked 8 of 15.

In response to the comment/question about shear stability (e.g. a 0w40 shears down to a 0w30 or a 0w20) take a look at the shear stability test in this report on pages 9-10. Royal Purple sheared low out of grade in both 40 and 50 weight tests.

Here is a quote from the report on shear stability:
"The results point out significant differences between oils and their ability to retain their viscosity. Within the SAE 40 group, 36% of the oils dropped one viscosity grade to an SAE 30. Within the SAE 50 group, 40% dropped one grade to an SAE 40. Most of the oils losing a viscosity grade did so quickly, within the initial 30 cycles of shearing.

It should be noted that both high and low viscosity index oils exhibited significant amounts of shear and viscosity loss. Two of the oils with the highest viscosity index, Torco T-4SR in the SAE 40 group and Yamalube 4R in the SAE 50 group, had the largest drops in viscosity of all the oils in their respective groups. Torco T-4SR sheared to a SAE 30 and Yamalube sheared to a SAE 40. Valvoline 4-Stroke SAE 50 and Castrol V-Twin SAE 50 had a comparatively low viscosity index and they too lost significant viscosity, shearing down to SAE 40."
:cheers
 

·
Registered
Joined
·
228 Posts
Discussion Starter #20
raven1124 said:
Not sure if that was a joke but he was talking about Mobil 1.
I thought he was referring to RP:willy:
 
1 - 20 of 29 Posts
Top