Finally got a compression test
 

Well, I bought my '05 new in February, 2006. We're at 29K miles now. Today it had its first ever compression test:

Rotor 1: 8.8, 9.2, 8.8 - 250 RPM
Rotor 2: 9.4, 9.3, 8.9 - 250 RPM

My mechanic said those are nice numbers - better, in fact, than some new 8's show fresh from the factory. To be honest, I'm not surprised; Car and Driver suggested that rotaries get better with age in their very first long-term RX-8 test:

"Racers say rotary engines get faster as they age, the engine's best lap always being the last one. The RX-8 didn't disprove the theory after 40,000 miles, cutting its drag sprints down to 5.9 seconds for 60 mph and 14.6 seconds at 96 mph through the quarter." — Car and Driver, September, 2005

Now I know there's a lot of panic about "engine failures" here on RX8Club.com and that a number of Renesis engines have failed their compression test and Mazda elected to replace – rather than repair – those engines. But I always suspected those early C&D results were more typical of Renesis performance. Not that you'd read about improved performance here, as owners understandably come here more to complain than to talk about how delighted they are with their cars; that's human nature.

Great numbers. Not that surprising though on a car that is driven very little (as I have always suspected) and is still on the original engine. Talk to me when you are at 143,000 miles. Kind of odd that your rpm is exactly 250RPM though, I have never seen that before..................

Post up a pic of the results from the dealer, I'd like to see the actual test results.

Thanks! Yeah, 250 RPM was on the sheet they gave me, but when I spoke to the mechanic in the garage, I asked him if I should consider upgrading to the newest starter (I have the revised '06 starter now) and I could swear he pointed to numbers better than that; like 270-290, is that possible?? So he felt the newest starter was, at least in my case, not necessary.

I think the good numbers are probably a combination of religiously staying on top of maintenance: frequent oil changes, maintaining oil level, not racing off when engine's still cold, lots of high revs, no engine mods, etc. Also I do a lot of highway driving; that's got to help. And maybe I got an especially good engine to begin with.

Still, coming up on 8 years, never flooded and no problem more serious than a squeaky sunroof. Guy said that even underneath, 'cept for a little on some bolts, there was no rust to speak of! (Disclaimer: I'm very anal about every car I've owned and they have all looked way younger than their age. My 8 looks like it's maybe… 6 months old? Wayne Mazda is a huge dealer and my guy said this was probably the nicest 8 he's seen. So yeah, I'm probably atypical.) :)

Could very easily see 270-290 rpm crank speeds during a compression test if the starter is in good health. When I had mine done, it was at 282 rpms. If those are in fact the normalized to 250 rpms at sea level numbers I'd say you've got yourself a very nice example of the breed. Better (but close) to the compression I had on my 09 when I got it at 25k miles.

Yeah with my S2 starter I see almost 300RPM. Those resulted are probably the corrected results but still they should have given you the actual results. I never trust dealer techs to do anything right. Do it again in another 8 years when you are at 60k.

Pics now attached.

Great numbers and very low miles for an 05. I bought mine in 07 and it has 40k miles now. I wish i have the same numbers as yours. Anyway, congrats for that.

Crazy, I have never seen one hit 250RPM on the head. Good numbers, but not surprising.

The trusty Android rotary compression calculator say it is out of spec :lol:

http://www.flickr.com/photos/9krpmrx8/10301400945/

I have never seen numbers that high at any RPM, but then again I have never done one "just cause" on a customers vehicle.