A lot of the people on the forum (including myself) agree that 5w-20 is too thin for the renesis. I run Mobil Super 5000 5w-30 (winter) or 10w-40 (late spring-late fall)

 

Hi, I did Castrol 5w-20 bout 3 mos. ago, sat for almost the whole time. Do you think adding 10-40 as needed would be OK till next change? Is the "3 mos. or 3k" rule in effect here?

Touchy subject, I know but I value opinions.
Thanks.

 

I wouldn't worry about the 3 months part of it. It is necessary to change the oil every 3k miles though because you don't get all of the old oil out when you do a change (you only get like 50% of it out during a change). Time isn't as important as miles (personally, I would change it every 6 months if I didn't always hit 3k before then).

It's perfectly fine to top off with the 10w-40 if you want to
But as j9fd3s said, you can also wait until your next oil change.

 

The other reason for frequent oil changes on mileage is that oil tests have shown conventional oil has typically lost it's viscosity by around 2,500 miles in the rotary. So if you use conventional, change it often for that reason more than any other.

 

5w-20 is fine, 90% of the Rx8s in the world run it, don't get their oil changed at all, and manage to still be running...

doesn't hurt to run something a little thicker, or synthetic, but you can just switch over next oil change.

 

Wow, I wasn't aware of that. I guess I should start changing it every 2.5k then. What causes it to degrade so quickly? Fuel dilution?

 

Heat and stress. The rotary is far closer to a diesel motor when it comes to the abuse it puts on the oil. Several members have had positive success with using diesel oil, though this requires you to run catless and a yellow tint will start showing up on the rear bumper soot.

Mobile1 0w40 tends to be what people gravitate to once they do their research. One of the big oil threads has a discussion about a Russian test of what heat does to a huge number of publicly available oils, and Mobile1 0w40 was one of the better results. If I recall correctly, Castrol Edge 0w40 is the only other one easily available in the US that was up there.


Here is the link to the test results, run through google translator, so some decyphering will be needed.
http://translate.google.com/translat...ed=0CDUQ7gEwAA

 

5w-20 is only used in 8s in the US. The 8s everywhere else run at least a 30 weight oil. And I'm pretty sure it's been proven that 5w-20 leads to premature bearing wear in the renesis.

 

Ah, that makes sense. The only diesel oil I can easily get is Rotella 15w-40, which is too thick IMO. The 0w-40 is a bit hard to come-by around here, and it's expensive. The price would be worth it if you could go farther than 3k on it.

 

Hi, thanks to everyone for replying! Lots of useful info there.
RX-8 Club rocks!

 

Installed Mazdaspeed shock/spring combo and left it at the local shop to get an alignment, feel weird about leaving it somewhere without me being around..

 

Leave. And don't look back. When I got lowered at a shop I watched.....it was scary! lol Today I cut the plastic mesh from my rear bumper. Guess I need to find some mesh.

 

I just got a flat tire today on the 118 freeway and couldn't get a patch done since the threads are already quite worn out. Right now, I'm running on three Bridgestone Turanzas and some cheap used tire for forty bucks temporarily until I buy a brand new set. I'm currently considering the Hankook Ventus V12 Evo or Sumitomo HTR Z III since they are close in price range... I wish I could open up to more choices like the Michelin Pilot Sport Cup or Continental ExtremeContact DWS, but they are way above my price range.

 

Stock size:

Ventus V12 EVO: $149 a tire
ExtremeContact DW: $154 a tire
ExtremeContact DWS: $161 a tire
Pilot SuperSport: $219 a tire

The ExtremeContact DW is only $5 more a tire in stock sizes than the V12 Evo. Do you need the "S" or Snow capabilities of the DWS?

 

My mistake, I overlooked the Continental DW over the DWS while searching earlier. Anyways, I have a 9" width wheels and currently running on 255/40/R18 and planning to stay with the same size; although, I've been thinking about saving a little money and going down with 245s. The Hankooks are $157 a tire plus $80 mail-in rebate compared to the Continentals which are $215 each.

 

Finished my air intake and thinking about removing my A/C belt as I don't use A/C, not sure if it throws a code if I take the belt off the A./C. Oh I washed it too

 

It shouldn't throw one unless the A/C belt also drives something else.

 

it doesn't

 

right it doesn't, buti think it has to do with my heat into the car?. I'm not sure any gains would be more than barely wrth it?.

 

i have a guideline; if i don't know what something does, i put it back, or leave it on the car. Mazda put it there for a reason, and if i don't know what the reason is i leave things alone.

if i know what something does, and i don't want or need that item, then it can be removed.

for instance, in a race car, you could pull the radio out, because you don't need it.

or, if you don't know how the AC is integrated with the heater, then just leave it.

 

Raced a Volvo S60 T5 because they were talking smack and beat them no contest. According to them, rotaries are for people who "can't handle the torque of a turbo". Not really sure what that has to do with anything, but they still lost

 

replaced the front half of the center console myself since the stealership wanted to charge me $200

 

V12 Ventus are the only UHP tires that offers a 20,000 miles warranty, I had the ContiSport Contact3 which I think felt very smooth and comfortable on the road. Handling on wet and dry is like how it was with my Direzza DZ101 but lasts longer and a little expensive. You won't need the DWS, you're just going to waste your money on those since we don't see much rain in SoCal.

 

I just bought the Hankooks two days ago. I can't wait till they get shipped and mounted on Tuesday. Paris (Atilla) I believe is also running on those Continentals. You're right about the price, they're around the four digit range for a whole set.

 

I freeway tested my home made ram air set up on my 2004 velocity red automatic 4 speed and it was really cool to notice the difference in pick up at speed: Most cool fun.