Topic: Royal Purple - Review

[blackdiamond]

Recently I noticed that the rear differential seemed to be running a bit warmer than I would like.  When I compared it to my 04 Tundra it was a dramatic difference.  The 85 (Detroit and 4.88 gears) was hot enough that I couldn't leave my hand on the differential for a long period of time whereas my 04 Tundra I could put my hand on it as long as I wanted.  I was concerned that due to my shims that my differential did not have the proper amount of fluid and figured that a synthetic product should also reduce temp.  I was actually shopping for 75W-90 Mobile 1 because I already had a couple of bottles; however, I was unable to find any at the local stores and ended up with 75W-140 Royal Purple Max Gear.  I jacked the rear axle up about 18 inches and "over" filled it with the synthetic oil, that is actually purple.  Today I drove it on the highway farther than I had when I previously compared temperatures and it was barely warm to the touch, the difference was actually surprising and amazing to me.  I wasn't really expecting much difference.  I honestly can't remember if I had the synthetic Mobile 1 in it before or a dino product, but Royal Purple reduced the temperature a significant amount.    Blackdiamond

[BigMike]

Cool, I've heard good things about Royal Purple Syn lubes

[Volcom]

Is it Ok to run 75W140 in the diffs?  Seems kinda thick for the gears.  I could be totally wrong since I really don't know the answer 

[blackdiamond [OP]]

Is it OK to run 75W140 in the diffs?  Seems kinda thick for the gears.  I could be totally wrong since I really don't know the answer 

I will admit that I was also confused about oil viscosity, but the 75W-90 is actually much thicker than the 75W-140.  The Royal Purple ran like water, it took about 5 seconds to empty a quart into the differential.  They have both weights on the website www.royalpurple.com and they both are OK for limited slips (no additives required) so I am assuming that it should be fine.  If the website is even half true it should be a great product, sounds like it functions similar to Lucas oil treatment that causes the oil to "stick" to the metal parts.

I just like the chicken.

[Weldo]

There was an article in Hot Rod magazine a while back about this stuff.  They put a Chevelle on a chassis dyno and made a pull, got a baseline, then they put royal purple in the motor, manual trans, and rear end.  They made another pull on the chassis dyno and picked up something like 13.4 HP!  I was extremely surprised by this.  13 horses from changing fluids!  Incredible.  Not only do you get the added performance and protection, but you can probably go like 6000 miles between oil changes.  Speaking of oil, you guys see that new Mobil 1 motor oil that claims you can go 15,000 between oil changes?  That's pretty cool, too, if it works as well as it sounds...

[UNBREAKABLE]

I was thinkin 'bout goin' synthetic in my D60+70 Just don't know how the Detroit will like it.

[mudguts]

The crude oil pipeline company I work for switched over to Royal P in all of our pump stations. It's dropped the temp of our speed increasers(aka gear boxes) by about 20 degrees. These are $80k+  units that run 24-7 and has cut down time quite a bit. It's good stuff from what I've seen.

[RokCrawlinToy]

I was thinkin 'bout goin' synthetic in my D60+70 Just don't know how the Detroit will like it.

Your Detroits will be fine, I've been running Mobil 1 in mine for about 2-3 years. I used reg. oil for the first couple of months after I put in my new gears & Det.
Thinking about trying Royal Purple in my other rides when I get around changing the fluids on them.

[blackdiamond [OP]]

The Royal Purple education continues.  I checked my differential temperature again the other night and it was much warmer than the 1st time I checked it after the change to RP, but  it was still running cooler than it did on conventional.  I am really puzzled      how the differential temperature can fluctuate so much with similar driving and environment.  I don't drive the truck everyday as I ride the bus to work, but I will be monitoring the temperature more closely and keeping everyone posted.  It sounds like other people have had good results with RP, I think that the key is synthetic vs. conventional and since  recommends AMSoil, I would be tempted in the future to use that brand.  I have been educating myself on synthetic oils the past few days on-line.

[guywithuglyyota]

I just switched my trans fluid to Royal, stuffs actually purple! Trans is noticably cooler to the touch after long drives.

http://www.royalpurple.com/techi/whyrpi.html

[blackdiamond [OP]]

I just switched my trans fluid to Royal, stuffs actually purple! Trans is noticably cooler to the touch after long drives.

http://www.royalpurple.com/techi/whyrpi.html

My differential has never been as cool as the first time I checked it, but it is cooler than it was prior to Royal Purple.  I have heard that some synthetics can be too slick for manual transmission and actually cause problems with the syncros.  Which specific product did you use and did you notice any other differences than temperature?

[guywithuglyyota]

Sorry to reply to you so late, well I just got back from a 1200 mile road trip from texas and I can say it shifts a bit smoother now since I serviced it with royal purple 85w-90.

I also threw a bottle of the purple ice in my radiator which is similar to water wetter, the temp gauge showed a very very slight drop in reading. From what I have read on other forums and just plain old word of mouth it aint bad stuff at all. Might actually prolong the life of the gears etc....but not recommended for newer trannys like you mentioned.

[blackdiamond [OP]]

My rear differential didn't like the synthetic, it started leaking more that it had previously (RP 75W-140), so I just switched back to Valvoliine 85w-140 dino oil.  Hopefully that will slow the minor leaking.

[blackdiamond [OP]]

Has anyone ever tried using engine stop leak or the Valvoline stop leak with seal conditioner in a differential?  I wasn't sure what it would do.

[fellowsped]

Speaking of oil, you guys see that new Mobil 1 motor oil that claims you can go 15,000 between oil changes? That's pretty cool, too, if it works as well as it sounds...

  the problem is is taht gas will get into your oil because your seals won't be 100% and gas doesn't lube well. i know several people who own shops and they curse that stuff. they say people will put that in and not check there oil and all cars burn some oil some more than others so they will bring it in for the next oil change and there will be like nothing in there for oil.  however i do suspect it's a good oil to use as i'm sure it does take longer for it to gum up and brake down but i wouldn't go 15000 miles with it i would only push it to maybe 5 or 6. but that's just my opinion

[kyle_22r]

uh, gas doesn't survive in a crankcase.  the heat alone pushes any kind of fuel remnants out the PCV system and back into combustion.  most syn oils will let you go 15k(hell, my '84 toy's recommended interval for normal driving was 10k), it's just that you have to change the filter more.  i'd maybe try it on a new engine, but probably nothing with 150k or over

[4x4fiend]

if your worried about running syn. oil in your tranny, i run synthetics wil a botle of Limited slip diff additve by Redline Oil in mine. it helps to make the oil "stick" and i noticed a difference. i would have rather gone with Redline MT-90 but i had lucas oil laying around so....