roboracer

Which brand of oil do you guys recommend? should I just go for Mazda oil?

w2aew

In previous threads, lots of people use Castrol. So far, with two oil changes, I've used Pennzoil 5W20. Stick with a major national brand, and be sure to get the proper weight and API Service rating of SL.

greese

I am also using the pennzoil.

Chief

I tried to get some Mazda oil from the dealer parts dept today, said they had it but couldnt sell it to me, that it's only for shop use or some ****.

Anyway I use Castrol GTX

BoxerGT2.5

I've used Castrol GTX as well...but am eyeballing some Royal Purple.

JSE RX-8

if you dont go with Mazda oil, go with Mobil 1. i havent heard any complaints yet and i know several turbo'd supras and IS300s that use it. just my $.02

NAVILESRX8

iTrader: (1)

Yep....Mobil 1.........that's what I use.

roboracer

so 2 for Pennzoil, 2 for Castrol, and 2 for Mobil 1...i'll just choose one of those three then...thanx for your help everyone

BaronVonBigmeat

I recently switched to Royal Purple 5W20, and it seems to work good. It could very well be my imagination, or coincidence...but it seems like I'm getting slightly better mileage.

I just measured my gas mileage today at 19.15 MPG for mixed city/highway driving on 87 octane, which sort of surprised me. I don't have the "L" flash either. I don't drive my car hard but I don't baby it either, typically shifting at 4-5k.

whosyourbaba

CASTROL!

ranger4277

I've got Royal Purple in the garage as well. Otherwise I'd be using Mobil 1.

BoxerGT2.5

How have you guys liked the Royal Purple??? Burn less of it?

w2aew

The "burn rate" is not going to depend on the oil, because the oil consumption is BY DESIGN. There are metering jets that inject the oil into the combustion chambers to lubricate the apex seals, etc. If a particular oil gives you a less than nominal burn rate, then I'd say you probably aren't getting the benefit of proper seal lubrication (read - short life).

ChrisR

Just out of interest for you the UK RX8 Owners Club have discount on oil for members at the moment 90% use Silkolene/Fuchs Titan 5-30W Semi-synth the rest Castrol A1 5-30W Semi

DAC17

Motorcraft semi-syn 5-20. I guess I'm just one of those guys that uses the viscosity recommended by the manufacturer. I know it's probably a CAFE thing, but I've always thought a lot of work goes into the recommendation that we don't necessarily see.

itsallaboutgary

PENNZOIL!

Gord96BRG

Yes, but it's worth noting that in the rest of the world outside North America, Mazda recommends 5W30.

Regards,
Gordon

DAC17

Gordon: Point well-taken.

Thanks.

Raevik

Penzoil here

colin204

I copied this info posted by gomez in the Australian forum from this thread https://www.rx8club.com/showthread.p...threadid=21105

Quote pasted by Gomez:
Finally got an answer to this age old question, and an official answer at that.
I have a copy of a parts bulletin, distributed to all dealers, for circulation to Dealer Principal, Parts Manager, and Service Manager which reads as follows: (Sorry, can't copy it onto the forum yet...technical issues!!!)

Date 17-9-03!!!!!!
Quote:
Due to some misunderstandings in the field in relation to the use of Synthetic and Mineral oils in rotary engines, National Technical Dept have created this Tech Tip in order to assist your staff with enquiries.

Pre- Renesis:
All Pre-Renesis engines have a set of oil control seals in the sides of the rotors, which are designed to keep oil from the lubrication system out of the combustion chambers. Each seal consists of a metal scraper with a rubber o-ring within.

MC advise this o-ring is not compatable with synthetic oils (or synthetic/mineral blends) and that such oils can attack the material in o-rings, causing them to break down and deteriorate. Should this occur, excessive amounts of oil would be drawn into the combustion chambers causing high oil consumtion, smoke from the exhaust, fouled spark plugs and reduced engine life.Therefore, synthetic oils or blends are prohibited and only mineral oils must be used in early rotary engines.

Renesis engine:
This engine has similar seals, which perform the same function as with the Pre-Renesis engines, however, the o-rings are constructed with a completely new type of material that has improved longevity and compatibility with synthetic oils.

While such oils are not prohibited from being used in this engine, MC still advises that mineral oils are more suitable with these engines. This is why MA will be importing mineral based 5W30 engine oil.

Genuine MC Engine oil for Rotary Engines:
We are currently in the process of sourcing genuine MC oil from Japan. This is a straight mineral oil with a viscosity of 5W30. There is quite an involved process to import this oil and then decanter it, which is the reason for the delay in supply to dealers. When available, this oil will be dedicated for rotary use, whether Renesis or early models and only available to the parts departments of our dealer network in 5 litre and 1 litre packs.

We will advise part numbers as soon as stock is available for sales.

Aldo Schepis
Part Business Manager.
End Quote.

zojas

why 5w-20 here, but 5w-30 everywhere else? what's the difference between 5w-20 and 5w-30?

G8rboy

I use Valvoline 5w20 myself... not sure if I'm going to switch to Mobil1 yet. Since I plan on oil change intervals of 2500 miles, I doubt the mineral vs. sythetic debate would matter much, except to my wallet.

Gomez

Hi Guys, note also that oil use is dependant on the rev's you average....ie, more rev's, more oil injected, therefore some guys with shares in Dunlop will have a greater oil consumption than the rest of us!!!

Gomez.

Nubo

Also on that thread was this pic (I added emphasis), which as far as I am concerned ends all doubt about use of synthetic oil in the Renesis engine, as well as the "requirement" for 5w20 weight oil.

zojas

maybe mazda says 5w-20 in North Americe because our gasoline and catalytic converters are different?

what part of the cycle is the oil sprayed into the rotor chamber? (what's the chamber called, anyway? in a piston engine, it would be the cylinder) I'm guessing maybe the oil mixes with the gas?