Royal Purple

[TheEndIsNear]

Hi all, I have been looking into going over to the Royal Purple Synthetic oil on my upcoming oil change. I am currently just running the standard 10w30 el-cheapo oil. My question is should I be using the 10w40, or the 20w50? Shes got lots of miles and a real prominent valve tapping that I will address as soon as I can get some time off work and a babysitter...

[ericcamaro]

thinner the better. allot of people run 0w40 mobile 1. id go with the 10w

[632 Regal]

same here, royal purple makes some decent full synthetic dextron II for the automatic crowd that requires it.

[ericcamaro]

will that stuff work in manual gearboxes that require ATF???

[onewhippedpuppy]

0W-40 is recomended by BMW, Mobil 1 if you want to be specific.

Eric, RP syncromax is recomended for manuals that require ATF. I put it in my 540/6, made a noticable difference in smoothness.

[BillionPa]

in josh's car i would go with Redline 5W40 in the engine over royal purple due to superior anti-wear characteristics and low temperature flow.

in addition, 40wt redline has a higher viscosity than 40wt royal purple at hot.

and im my auto trans i am running a 50x50 mix of Redline D4 and B&M TrickShift synthetic, and its the smoothest transmission with the fastest lockup of any car i have driven.

[TheEndIsNear]

Hmmm, 5w40 Redline. I'll do some research on that... BTW, I'm an aggressive, high reeving driver...

[Kalevera]

Personally, I'd use Mobil 1. But, remember that the M20 was designed for regular dino oil, and that's what they've always gotten from dealers. There's no reason to spend extra money on more...exotic oils if the change intervals are kept something like regular.

In the case of manual transmissions and ATF: I prefer the redline fluids, specifically MT-90. We almost exclusively use Royal Purple fluids -- synchromax and max gear are fine products, but if money isn't a concern, I'd still use redline stuff. I've run three different fluids through my trans in the past month: regular Dex III ATF, synchromax, and MT-90. The synchromax was the noisiest of the bunch, but shifted better than regular ATF. MT-90 is quieter than ATF and shifts better than synchromax once warm. Granted, this is on an old G260.6 -- I've never noticed more or less noise in using synchromax in any other transmission. Also, there's a SIB floating around that discusses the use of ATF in manual transmissions, and what fluids to use in response to a noise or shifting complaint.

best, whit

[TheEndIsNear]

Very interesting information... My transmission shifts kinda hard between 1st and 2nd (automatic) but is fine the rest of the time... Is this normal or could it be fluid related? It shifts hard enough that if I lay on it she will peel out on the shift into second... Other than that shes soooooo smooth for 249,000 miles...

[ThoreauHD]

At what mileage did you change the transmission fluid? I'm hoping that you have.

[TheEndIsNear]

I've only had the car about 60 days now, that translates into about 2,500 miles. I've done one oil change right after I bought it, but other things took priority like the not working break lights... She is my daily driver, and I wish I could poor so much more money into her but alas, the budget of a single dad... How often should I change the transmission fluid? I tried to track down a maintenance schedule, but without luck. I was told the warning system on the car would tell me what service I need and so on... I really haven't had too much time to look into it farther.

[SharkmanBMW]

be careful with the tranny... there is a lot of good info here, don't flush it... read up.

[TheEndIsNear]

I'll do that... Thanks...

[ajt3nc]

Before I rebuilt my M20 it was noisy and I tried a few synths with no change. I put a straight 40 for mileage dogs in and it was quiet till I spun a main. The main spun because of my heavy foot, not the oil.

[TheEndIsNear]

Just an update, decided to use the Mobil 1 0w40. I'll be doing the change out later this morning.

[bfd]

will that stuff work in manual gearboxes that require ATF???

For my 1990 535i, 5spd, 106K miles, I'm currently using Royal Purple's Synchromax in my manual transmission and RP's Max-Gear in my differential. My tranny shifts smooth and the stuff is cheap. Then again, prior to this last change, I had been using Redline MTL and diff fluid and had no problem either.

Key - since synthetic fluids are cheap, change it regularly, i.e., every 25K-30k.

[Qube]

A little OT, but KUDOS for being Single Dad and holding strong! I see you have a pic of both your precious babies in your signature :)