SCCAGT

Everyone has heard the line, "Ive used brand XXXX for years never had a problem". Fine and dandy!! pulled the info below straight from a product test brochure. Believe it or not. Doesnt matter to me. I know what goes in ALL of my cars.


-In a test involving 14 different 75W90 gear oils, Royal Purple FAILED the SAE KRL Shear Stability test, which involves initial viscosity and shear stability requirements. Which means every paramenter of the SAE J306 requirements were not met as well. Only Lucas performed worse.
-RP and Lucas both failed the cold temperature Brookfield requirement for 75W gear lubes.
Castrol Syntec, RP, Torco, Mopar, Redline (worst), all had 15% or greater viscosity change in the ASTM-D2893 and D-445 oxidation test.
-ASTM D-4172 4 ball wear test, Pennzoil, Castrol RP, and Valvoline all allowed metal-to-metal contact at 1250 lbs, which is less than half of all other tested oils.
-Mopar, RP and Lucas failed ASTM D130 copper corrsion limits.

The 75W90 gear oils in this test were: Amsoil Severe Gear, Mobil 1 Synthetic, GM Synthetic Axle, Castrol Syntec, Redline Synthetic, Pennzoil Synthetic, Valvoline Synpower, Castrol Hypoy C, Torco SGO Synthetic, Valvoline High Performance 80W90,Pennzoil Gearplus 80W90, Royal Purple Max-Gear, Mopar Synthetic, Lucas Synthetic. This is also the actual order of finishing results from best overall to worst overall.

For Redline users, here is how it ended up: 7 1st place finishes, 1 3rd place, 1 5th place, 2 6th places, 1 8th, 2 9th, 2 10th, and 1 14th.

When the oils met or passed testing criteria, they were all given a 1st. Example: all but Valvoline High Performance and Lucas passed the Channel point" test. 12 oils were given 1st (tie) and the other two were given 13th (tie). Points given were placing positions. Like golf, the higher the points, the lower the resulting finish..

Amsoil is the only company with the "cojones" to do testing like this AND publish results ( I LIKE that. Try finding info from any other brand). Amsoil had an outside company perform the testing at Amsoils expense. Amsoil had performed better than any of the 14 brands in 8 out of 17 tests. Place 2nd in 5, 3rd in 1, 4th in 2, and 9th in 1. The 9th place was in price comparison. This information is available to anyone who wants to find it on your own, or order the information brochure from Amsoil simply called "A Study of Gear Lubes".

BillyBobJoe

I currently have RP in my engine, did the swap at about 8K. Should be coming up on 13K soon at winter break and plan to swap to Amsoil for the engine. I'm not touching the tranny for a long time. But because I have some RP gear oil I'll be swapping out the rear end fluid over winter break also.

blownperformance

We have tore down alot of engines andI have noticed a considerable diffrence on the "wear" between the diffrent oil brands. Amsoil in my experiences has held up and preserved engine vitals far better than RP, mobil, and Quaker State. I run it in all my cars i build for myself and customers.

ChiDiddy

^more testimonies to back up my own negative experiences with RP.

I only use Amsoil and M1. Strictly Amsoil when it comes to transmission and drivetrain fluids (in highly modded applications like F/I of course). Amsoil ATF is by far the best. Meets ALL and exceeds the requirements for most trans fluids, including the nit-picky Honda/Acura Z1 ATF. Keeps my RSX auto trans alive with all the boost i'm pushing.

AmericanMuscle4.6GT

****.

i already ordered the RP.


come on though............motorweek did a before and after dyno on a bone stock LS1, and got 8 rwhp. good enough for me.

ChiDiddy

you're more concerned about dyno numbers than engine wear? From what i recall, that LS1 was not only running RP oil, it ran straight distilled water with Purple Ice coolant additive, RP trans fluid, and some other RP products. 8whp is not a significant enough HP gain to really say its a gain. 10whp is usually the margin of error for dynos in between before/after tests.

Since you already bought it, i would change it every 5k miles or less.

BillyBobJoe

I wouldn't worry, Like I said I've had it for almost 5K miles and I've had no problems. No knocking, no smokey exhaust, or anything to worry about. Actually, I've heard most people say RP is the way to go until this post.

AmericanMuscle4.6GT

yea this is the first time i've heard anything other than praise for royal purple.

ChiDiddy

you wont have any problems with it for low mileage. Its the extended use and long-time wear on the engine that may occur.

the only way to test if RP is doing well for you is to get an oil analysis after an oil change. http://www.blackstone-labs.com/
They will tell you about any wear on the engine and make recommendations on the time/mileage intervals. A routine oil test is a great way to test for any wear over time and will help you diagnose what you are doing wrong.

I'm basing my opinion off my own results. Everyone should not go with heresay or whatever, every car is different. Use whatever works for you, and verify it yourself with the oil test.

AmericanMuscle4.6GT

bump.


i dont see a problem with RP. its so widely used, and almost everyone i've known whos tried it was impressed by the results. i don't think it will cause me any problems on a near stock motor..