My recently purchased RX-8 showed 6.7-7.0 compression results on all 3 faces front and rear. It’s previous two owners were 65+ years old. I’ve put 1,000 miles on it since I took over ownership and have been redlining it 5-10 times per drive. I tested the car last Saturday out of curiosity at Rotor Torque, and the car showed 7.1, 7.5, 7.2 and 7.6, 7.3, 7.4.
Point is just drive it. Don’t worry about compression too much if it runs well.
Very good point and I am actually in the same situation as you. Got the RX8 about a month ago, owned by an older person for last 15 years and the car saw very little use in last 10 years. Initial compression test showed 6.5 to 7.1. I have now double changed the oil to 10w40 Millers Trident and have completed ~1000 miles already. I was thinking of getting another compression test at the same specialist in a month or two to see what difference it has made. Good to know yours have improved noticeably. I am premixing with Idemitsu rotary lube and redlining it a few times on the 20+20 miles commute every day.
Having owned Italian cars and motorbikes, I am used to the "Italian Tune up"
Yes, sometimes it does work. I also saw compression rise over time on my FD RX-7 as it went from mid 7s to an average of 8 bar over 10,000 miles due to a better tune and the use of water injection which cleaned out the carbon over time and kept the plugs looking perfect.
Obviously, in the RX-8 case too much time spent at 9500 RPM isn’t great given the engines aren’t balanced well, but most of us aren’t hanging into 3rd gear heading into a corner at Snetterton or elsewhere putting that kind of strain on the car.
These users thanked the author cib24 for the post:
Well, the results were irrelevant in the end, as the seller cancelled twice when I'd arranged to go and see the car, and it's now been removed from sale??
There was another 8 for sale in Inverness but when asked about hot starting the seller replied it sometimes took 10 - 15 mins to get it to start.... And I've more recently seen it advertised on Facebook etc as "starts 1st time every time!" ... really... there are some clueless/unscrupulous sellers out there.
So I did what I should have done in the first place, and bought a 40th Anniversary model from a member of this very forum!
These users thanked the author hachiroku for the post:
Well, the results were irrelevant in the end, as the seller cancelled twice when I'd arranged to go and see the car, and it's now been removed from sale??
There was another 8 for sale in Inverness but when asked about hot starting the seller replied it sometimes took 10 - 15 mins to get it to start.... And I've more recently seen it advertised on Facebook etc as "starts 1st time every time!" ... really... there are some clueless/unscrupulous sellers out there.
So I did what I should have done in the first place, and bought a 40th Anniversary model from a member of this very forum!
Starts first time……………after cranking for 15 seconds!
Rotary History;
Sep 2005-Aug 2006 EO55 XOL VR 231 New
Oct 2014-Mar 2019 OE06 EWJ VR 231
Jan 2019-Jun 2020 T200 CAD Orange SC 231
Feb 2020-May 2023 RR54 AJR VR 231 Modified for Track
Oct 2020-Mar 2021 YA56 EUE Copper Red Nemesis
Jun 2022-Apr 2023 TN07 JHD KURO Resurrected
Jun 2023-Jan2024 OV09 BFF Sparkling Black
I am premixing with Idemitsu rotary lube and redlining it a few times on the 20+20 miles commute every day.
