Had my first autocross in my new 8 last Sunday. With the Koni Sports set full hard front and rear and some old Nittos which I purchased from a friend, all I can say is that this car is awesome. Awesome even when compared to my CSP Miata. Well, I need a lot more work, but the 8 is great!

That said, what do you folks recommend for autocross and/or DE days as far as the weight of motor oil is concerned and why? I plan on switching to Royal Purple now that the car has over 2,000 miles on it. FYI: During the first 2,000 miles the car needed only 1 quart Castrol GTX added.

Thanks!

 

5-30w

 

5W20 because that's what the factory recommends. They also say NOT to use synthetic so think again before the royal purple. I put about 15-20 autocrosses on my 8 with regular Castrol 5W20 and no problems.

 

gastrol gtx 10w40 has helped my oil cooling a bit on the track.

 

put in what you want after research, u'll never get an answer here, i use 10w-30

 

The unofficial "factory" Mazda road race team runs 20-50 Pure Power. www.gopurepower.com

 

Keep in mind that autocross and road racing place very different demands on lubricants. In autocross, you don't acheive or maintain the same temps you do in road racing, so (in theory) you would go with a lower viscosity to both get to operating temps quicker and also reduce power lost to moving around "thicker" oil. In road racing, temp management and maintaining the oil's integrity at higher temps becomes more important.

While Mazda explicitly reccomends NOT using synthetic oil in the RX8 owner's manual, know that Mazdaspeed (and most all Mazda racing teams) do reccomend and use synthetic for "high stress" conditions.

 

Pure Power is not synthetic. You are right about the temps, I use 10-20 Pure Power for autox. I asked for 5-20, but they told me they only use oil than thin for washing parts.

 

I was referring to the OP, who is considering going to Royal Purple...which is synthetic and also reccomended by Racing Beat...

 

I've always run 5W20 Castrol GTX for everything, but then it's a dedicated autox car so that's everything

 

Did you get an official statement from Mazda Canada that 5W30 is recommended? My manual says 5w20 and that is what the dealer puts in it for oil changes.

 

http://www.mazda.co.jp/service/owner...x-8/70201.html

i trust the Japaneses, especially since they breath the same air we do.

http://babelfish.altavista.com/babelfish/tr for translation

 

20w-50

 

ThecdnRX8
I called http://www.upperperformance.com a few weeks ago.

If I remember correctly (my notes are home and Im in Vegas), they sell royal purple for 8.50 a liter, and 7.50 a liter if you buy a case.

Check them out, they are in lachine local.

There is also the other place on St-charles, however they are more expensive.

 

That's what I used in my FC RX-7 and it loved it.

I'm going with 10w-40 on the RX-8 and I expect good results as well

 

10w40 worked well for me in N/A form. It looks like I will have to switch to 20w50 if I want to keep tracking my FI car.

 

10w-40 on street, 20w-50 for HPDE.
Almost no one in the SE region is running 5w for anything any longer.

 

Thanks for all the input. What I can glean from all of this is that there's not necessarily one answer to the question and some of the conclusions are naturally a bit subjective. I've read most of the threads regarding synthetic oil, the historical problems with Mobil 1, and so forth.

With that said, I've decided that the 5w20 RP may be a bit thin. As I already have 6 quarts of it sitting in the garage, I purchased an additional 6 quarts of 10w40 RP and will use them 50% - 50%. This, gentlemen, is what compromise is all about!

Regarding synthetic oil, my daughter's 97 Cavalier Z24 has been sipping Mobil 1 since new, with the oil and filter being changed only once every 7,000 to 9,000 miles due to her being away at school and so forth. When the pan was dropped after 108,000 miles it was amazing. You could have eaten off it and the engine internals.

 

save the money and just use 5W20 dino oil ...

 

how about 10-30? thats what mobil recommends on their website.

i've used 5-20 regular and now synthetic. i liked how the regular felt at first but how the synthetic felt after a couple hundred miles. is that just me?

 

Just a note, oil is not rated by weight. The correct term is "viscosity." The "W" stands for winter.

 

There are some good recommendations from Mazmart on Expo1's engine rebuild thread. He tracks his car often. They saw significant bearing journal wear at 100K miles and recommend going to a thicker oil.

 

No way in hell would I race around with dino 5W20. Well, if you don't like your car or don't mind early engine death, than sure 5W20.

At least synthetic 5W30 or 0W30. However the recommendation for that is for daily driving, broad range weather conditions, morning engine start up, etc....

Strongly look into a synthetic 10W30, 10W40, or 20W50. 10W40 synthetic would be the conservative and less controversial choice for racing.

Strongly look into pre-mixing with 2 cycle oil OR using a lubricious cleaner as the pre-mix like Lucas UCL or Lube Control FP Plus as the pre-mix (I would go with either of the latter 2).

Considerations would be the amount of sustained high revving of the engine, duration time of race (shorter race and less high revving= thinner oil and long race and continuous high revving= thicker oil), gas mileage concerns, attempts to squeeze out a little extra HP, outside temperatures, etc...

Have Fun

 

20w-50 per its ability to take heat, was told that it was the best weight to use by Speed Machine when I had my FD tuned there.