I think you need to quit believing urban legends.

Please read up on kinematic viscosity. It's a common misconception, but oil's viscosity does not "climb" (or increase, go up, etc) with temperature. they all lose viscosity with temperature. the SAE numbers used on the oil grade are a representation (key word here, implying that it is not absolute, but rather a range) of that oil's Viscosity Index slope of temp vs. viscosity. 0W-40 means that it 'acts' like a 40W at a reference 'hot' test temperature of 40C. but despite the implication, this viscosity is much, much thinner than when the oil is tested at its "0" viscosity state.

castrol syntec blend...best of both worlds...

Castrol GTX 5W-30 as of 13K miles.

I switched to Motul 0W30 (ester based), some I'm "other" now.

DEXELIA 5w-30 official mazda europe oil for RX8

Mobil 1 15W-50
 

At 100 miles on the odo, I drained as much of the factory fill as I could (about five quarts) and replaced it with 15W-50 Mobil 1. Why so high a viscosity? Because it gets so damn hot :rant: here in Phoenix, and because of this thread: https://www.rx8club.com/showthread.p...light=oil+temp which indicates a high viscosity oil will run a bit cooler at higher ambient temps.

whatever the dealer puts in, at $25 a oil change and car wash, I don't bother with it.

Sticky Sticky

castrol gtx all the way....

Castrol GTX 5W-30 non- synthetic for 100 miles and the exhaust smell is not a strong

So which oil Mazda dealers use? Does it vary from dealers to dealers?

I like to feel like I'm REALLY one with my car, so I chug a bottle of Castrol GTX every morning before heading off to work.

It does vary, it's pretty much up to the dealer. The one I bought my car from uses Castrol GTX; the one I take it to now uses Chevron Supreme.

I was using Castrol GTX 5w 20 since I purchased the car. I had a new engine installed under warranty in June. Upon getting the car back I installed the Sohn OMP adapter and am using Idemitsu premix in the Sohn resevoir. I use Royal Purple 10W 40 in lieu of the Castrol GTX now. I guess we will see the results at the next rebuild.

nice thread bump lol, just a few years but good thread I guess

I thought it was a good thread. I'd like to see if the results have changed in the recent years as far as what type of oil people are using. No need to reinvent the wheel here this thread seemed to be put together nicely. Are more people switching to synthetics being alternatives for the omp have been developed like that of the Sohn adapter?

Well since its already been bumped ... I checked 'other' , Penn. YB 5/30 here

The sohn adapter esisted for a long long time before this thread was posted.
There's also who machines the center of the rotor tip to provide lubrication "from the inside", just for reference :)

bse50 thanks for the history I was not sure how long the Sohn omp adapter had been in production. I guess I had figured it had been out for many years since it found its roots amongst RX7 enthusiasts. I guess what I had meant is I had been hearing of alot of RX8 owners installing the adapter recently. Thanks again.

Mobil Clean 5000

I use bertolli olive oil

I love bertolli....... as long as its extra virgin! :yumyum:

vast differences = ?

I run RP 5w20.

Im too cheap, so I run GTX 5w20.