Models · Mazda
Mazda RX-8 buying guide
Mazda's four-door, four-seat rotary coupé, built from 2003 to 2012 and sold in the UK until 2010, with the 1.3 Renesis twin-rotor engine. Engine condition varies from car to car, and a proper compression test shows where a car stands.
The versions
- Renesis 192PS (four-port), five-speed manual, 7,500rpm redline
- Renesis 231PS (six-port), six-speed manual, 9,000rpm redline, variable intake, extra oil cooler and uprated suspension
- Late 2008 facelift: restyled, stiffer body, revised rear suspension and a much-revised engine lubrication system
- R3 (UK from August 2008): Recaro seats, Bilstein dampers, 19in wheels and a faster starter
What to check on a RX-8
3 model-specific things to look at when you view one. They're a starting point, not the full inspection.
A rotary compression test
What to look for: Ask for a recent compression test done with a rotary-specific tester, and for the printout showing all three readings per rotor and the cranking speed, not just a pass. If there isn't one, have one done before you buy.
Why it matters: Gradual wear of the apex seals and rotor housings causes lost compression, hard starting and reduced power. Mazda's standard is 121psi with a minimum of 98psi at 250rpm; engines in the high 80s to low 90s may still run well but are nearer a rebuild. A piston-engine tester gives meaningless readings, and a faster aftermarket or R3 starter can flatter the figures.
Hot restart
What to look for: Arrive with the engine cold, drive until it is fully warm, then switch off for 5 to 10 minutes and restart. It should fire promptly, in under about two seconds. Note long cranking or a struggle to fire.
Why it matters: A worn engine often struggles to restart when hot because compression is low, and weak coil packs can cause the same symptom. Together with the compression test, it is the best guide to the engine's health.
Ignition coils and misfires
What to look for: On the drive, note any hesitation, stutter or flat spot, and listen at idle for unevenness. Ask when the coils and spark plugs were last replaced, and check which coils are fitted.
Why it matters: Weak coils cause subtle misfires, and the unburnt fuel washes oil from the rotor housings and overheats the catalytic converter. Original coils are treated as about a 30,000-mile item, Mazda's plug interval is 37,500 miles or three years, and counterfeit coils are common. Regular coil and plug changes are a sign of a car that's been looked after.
Also in the full guide
- Rear arches, sills and the oil cooler pipes
- The cold start, test drive and paperwork checks for the exact version you're viewing
The full guide to the RX-8
The CrankSight guide walks you round the car on your phone at the viewing, with every check for the exact version you're looking at: what to look for, where to find it, and what anything you find is likely to cost. As you go it builds an assessment of that car, and if you view more than one, it lines them up side by side.
£29 for the model, used on as many cars as you like, delivered within 72 hours or your money back.
General points for the model, last checked October 2026. Every car is different, so treat this as a guide to what to look at, not a verdict on any car. CrankSight is independent and has no connection with Mazda.