OK so I was looking into Racing Beat's Web site and all they sell is Royal Purple Synthetic.


I asked and they said it is totally fine to use them on the RX8...infact they recommend it.


Maybe I am old school since owning an FC RX-7 (made it to 250,000 miles) and now a Series II RX-8...but I have never used Synthetic on them cause the manual says not to...Now on the RX-8 can use synthetic according to Mazda, but not recommended for long term.


So I'm really a bit confused...


How many of you guys actually use synthetic and never had problems and past over 150,000 miles?

 

I've heard very few good things about RP as of late.

Especially if it's not in a Mopar.

I run syn. I know many others who do as well. I can't name any who use RP.

Perhaps someone here has and can chime in

Travis

 

Hows your engine? Have you run it for a long time?


I know that Synthetic cools and lubricates better but I stayed away cause Mazda don't recommend for long term use and that's the only reason why I don't use it...

 

While I've ran Royal Purple once or twice to no ill effects, I tend to stick with Mobil 1 0W-40. But I have an SOHN adapter. I did use Mobil 1 synethic before the SOHN with no problems (93k on the original engine and counting).

Here's what truly turned me off Royal Purple, even though my 8 will hopefully never see these conditions:

 

Do some reading on the subject. There are PLENTY of threads on the issue.


The fact is, there is ZERO definitive proof that using synthetic oil causes additional wear OR less wear on the engine. Read. Educate. Decide.

 

RP isn't bad but it's also not particularly good. There are better for similar or less money.

 

Looks in the used oil analysis thread, Paimon had his tested with less than stellar results after only 1500 mile intervals, RP then tested it themselves and got the same results.

It's not horrible, but it's not worth the price.

 

Mazda America said that RX-8 can use synthetic? Where did you hear that? I always thought they are still insisting 5W-20 conventional.

Personally, I run just that, although I will get my used oil sampled to see if I need to bump up to 5W-30. Rotary does run quite hot, and 5W-20 can be less stable under higher temp.

Conventional is just fine if you change oil often.

I don't use Royal Purple because like others said, there are far better stuff you can buy than RP.

 

Synthetic is bad MMMMkKKKKAAAYYYY

 

IMO having oil in any car is better than none. I ve used RP on my rx7s 20w-50 and I ve used whatever is on sale too. Never had any issues. I just bought an rx8 its not my daily driver so I will stick with the 5w-20 but I always thought 5w-20 in winter and 20w-50 in winter. I don't drive my rx7 or 8 in winter much because of the salt on the roads.

 

Saw that thing before here. I think someone actually bought one and kept the can as a souvenir of sorts. Personally, I'd buy it just for the can. A quart of that stuff costs the same as a big jug of oil in your local store, and that's before all the import and shipping fees, which are also high because it contains a liquid. Not a financially feasible idea.

The thing that still concerns me is the fact that there are so many base stocks for synthetics, it's hard to predict how they burn(which is also Mazda's concern). Heck, Pennzoil makes synthetic oil out of natural gas now(though it's not really a new technology). I have seen people here complaining about Mobil 1 synthetics leaving behind some residue in housings. Conventional oils are pretty much the same save for the different detergent package, which means fewer variables.

 

The M1 leaving residue is nonsense. And Mazda oil is usually Castrol so this is likely just rebottled Castrol Edge 0W-30. I mean it's like BMW they recommend BMW specific Turbo engine oil for my 335i but my oil cap says to use Castrol Synthetic only. It's just oil.

 

They said it on the ownership video...

https://youtu.be/1Mi97U1yZsM

Synthetic is compatible, but long term effect is unknown...

 

Mazda has historically not recommended synthetic oil, but I suppose we know by now that synthetic should be fine.

That said, with the short oil change interval on the car, I doubt I will really benefit from synthetic oil, and synthetic oil is kinda pricey.

Hmm, I'd think maybe Mazda Japan uses a different brand.

 

Products at Idemitsu Lubricants America Corporation

 

You might assume that like most people, but maybe a Renesis using synthetic oil just dies for a different reason ...





....

 

That's interesting. In olden days, you had to worry about the seal compatibility problem when switching any engine to synthetic oil. Seems that's less of a thing now, but I also wonder how that 2006 recommendation has aged. Oil specifications have moved forward and there is a wide variety of synthetic formulations in the market. Would love to know what specifically in the oil attacks seals. I imagine that Syntherenesis stuff doesn't contain it, maybe we can identify other "safe" oils.

 

Well theres nothing I've seen that shows any difference for Renesis engine life whether mineral or synthetic. So even if it's ok to use, an argument can be made for not spending any more for oil than necessary too.

 

No,....... Mazda's former Dexelia 5W30; now marketed as ULTRA 5W30 is bottled and supplied by Total/Elf (France). Their present (the same) equivalent oil is Total Quartz Future 9000 5W-30

Because of lagging sales figures of Dexelia oil and the better additives available today, for a couple of years Total/Elf changed (source Total Service MA ) their recipe for the Mazda oil, which now is equivalent to Total Quartz Future 9000 5W-30 .................

 

^That.

If you change oil often, most of the benefits of synthetic become moot points. I personally wouldn't run my oil for more than 5k km(3.2k miles), and conventional oils tend to go on sale more often in Canadian Tire, so I just pick up a couple of jugs of Pennzoil yellow/Castrol GTX.

Also, seems like the older GTX conventional is discontinued. The ones in the store now are this synthetic blend... Bummer. Does anyone in the States see this change? Looks like I might have to go back to Pennzoil yellow in the future...

 

Well I haven't seen what specific rubber material is being used there. Without that info it's hard to be sure that Mazda is off base or not. However, for the engines that end up puking engine oil into the intake this is exactly where the blowby is coming from. Something to consider.

 

I'm betting on frequent oil changes using cheap SAE-SN rated oil. I chnage it every 1000 miles using whatever is cheapest (Autozone brand SN rated, etc.). I've been doing 3000 mi oil changes on my old Integra GS-R using cheap dino oil and got about 250000 miles on her before a drunk ran into/totaled her. Since oil lubricated, is injected, and cools, clean oil is king. I intend on keeping my 8 for a lifetime.

 

It's more likely to be a long term durability issue. Most race engines will never see that kind of extended mileage/ hours. Though I have tried a few different synthetic engine oils at various times, I generally prefer to run non-synthetic oils; Castrol GTX early on, mostly Valvoline VR1 20W50 race oil since then. The VR1 high zinc level could be an issue for cat converters over time though. Never seen even the slightest hint of oil in my intake ever. The one high mileage street engine I know of that was puking oil was run exclusively on synthetic oil and I'm pretty sure it was RP no less. Even had an RP oil filter on it.

 

If I am reading that memo correctly, the oil blow-by problem is in rotary engines before the Renesis, meaning not affecting the RX-8.

The RX-8's troubles have to do with carbon buildup in the inlet ports, supposedly.

 

It's actually much worse on the Renesis due to side seal placement, side exhaust port effect on side seals and also the heat, and intake port size all of which are different than the earlier engines.

Feel free to keep banging your head on the wall.