Which is better? Redline or Royal Purple?
 

Gonna be changing my tranny and differential fluids soon... so, So which is better? Redline or Royal Purple? Anyone?

Royal Purple 'Max-Gear' is very highly rated, but mostly by racers, who care more for performance than longevity.

Redline is, I think, a step above. Best reputation in the oil business, bar none.

We are blessed with a drain plug, so never have to take off a diff cover to change the oil, but 'domestics' usually do, and you can see an immediate difference on the gears. Check a differential with Redline, even after it has sat overnight - the gears still have a thin red coating of oil on the surface!
Tenatious stuff, and try not to get it on your mitts as you change it - it will stick to skin the same way.
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doc

Most of my friends that have owned RX-7s have used Royal Purple.. they swear that's the ONLY thing to use. :P

I used Royal Purple MaxGear in my RX-7 (tranny and diff) for years with nothing bad to say about it. I never compared it to Redline, however I've never heard of anyone complaining of troubles with it. Or Redline for that matter...I don't think there's a wrong answer here. Either one is good stuff, so if one is significantly more expensive or harder to find...get the other one.

It is a logical fallacy to infer that Redline is better in terms of longevity because racers use Royal Purple and racers are not as interested in that trait.

jds

Yeah, they're pretty similar - I think you're really splitting hairs trying to figure which one's best. They're both lightyears better than plain gear oil.

I usually just get whatever's easiest or cheapest to get - either Redline or Royal Purple. Both are excellent products.

Dale

i have used royal purple on my rx7's
never tried redline before
but some viper guy i knew used it.

Royal Purple user over here. Royal purple Synchromax in the gearbox and Max Gear in the diff. Smoother shifts and less noise from the rear end.

Tony says, "Two thumbs up!!"

Royal Purple makes some good stuff. My overall favorite is Amsoil though.

as you can plainly see, all great products. get the cheapest one.

I already ordered the Redline. :D

I've got redline on the way too :)

I put Red Line (it's two words people and here's the link http://www.redlineoil.com/) in transmission / differential.
rx8cited

I got Royal Purple in both DIff and tranny. Got rid of that whirring noise the car made when cold, adn feels nice and smooth.

Tony: Acording to the guys at RP, do NOT use Synchromax in the RX-8's diff. Let me quote:

"The differential needs a gear oil - like our MaxGear 75W90.
DO NOT USE Synchromax in the differential. It is the fluid consistency of an ATF and your differential will not last."

According to:

David Canitz
Tech Services Manager
dcanitz@royalpurple.com

Ok, my understanding is to use Royal Purple MaxGear 75W90 in both DIff and tranny.

What is the exact Red Line product(s) to use? MT-90? 75W90 Gear Oil? I went to their website and got myself all confused...

Thanks for the tip Genom, but re-read my post:

I appreciate your concern, though. :)

https://www.rx8club.com/attachment.p...chmentid=26627


BTW gear oil stinks :D

For Red Line, use MT-90 in the tranny, and 75W90 Gear Oil in the diff.

Edit: Or do what I did and use the RP MaxGear 75W90 in the diff, and Red Line MT-90 in the tranny...

Ok, thanks guys. That's what I kind of thought. Good to know for sure. :D

Thanks again!!!!!

And agreed, gear oil stinks big time!

as anyone used redline water wetter..?

I added some (small bottle) and noticed no difference

I used a 12oz bottle and notice no difference in the temperature guage or performance of the car.

I wonder how many degrees each tick mark on our temperature guage corresponds to?

BTW it is Red Line (two words) if you care ;).

rx8cited

If your using water wetter you need to purge your cooling system first to get the right mix since it uses way less antifreeze than normal. You also wont see a difrfernce in the gauges, but the car should run better in high heat stuff like autocrossing and HPDE events.

Not necessarily for my use. 50/50 is okay as I'm not trying to maximize the temperature drop.

Here are the directions from thier data sheet:

"USE DIRECTIONS
One 12 ounce bottle treats 12-16 quarts of water or a
50% ethylene or propylene glycol solution. In smaller
cooling systems, use 4-5 caps per quart. Add directly
through the cooling system fill cap into the radiator or
into the overflow tank. Do not open a cooling system
while hot. For best protection for aluminum, replenish
or replace every 15,000 miles. The anti-scaling ingredients
in Red Line WaterWetter® allow its use with
ordinary tap water. However, using with distilled or
deionized water will accomplish some scale removal
in the cylinder head area. Plain water with or without
WaterWetter® should not be used in cooling systems
containing magnesium - antifreeze should be used -
with WaterWetter®. For maximum temperature
reductions use the most water and the least
antifreeze possible to prevent freezing in your climate.
Even in summertime the use of air-conditioning
can blow freezing air through the heater and cause
freezing of the heater core unless approximately 20%
antifreeze is used. Red Line WaterWetter® is available
in 12 ounce containers."

rx8cited

Hey guys.. here are some measurements that I took from my CANScan regarding the coolant temp.. I just so happened to also be tracking my air temp at the time. I plan on adding water wetter and then running the test again to see if there is any difference...

Here are my results so far..

The temperture was 58 to 60f.

The spike that you see after 10 minutes was me pulling over for a few minutes to test how hot it would get just ideling.. Gets darn hot :)

After this brief stop, it returned to normal.

I am hoping to see my car run at 170 or lower consistently.. we'll see :)

Cool, Dave. If it works, then I'm gonna get Water Wetter, too.