Mazda RX-8 Coupe (2003-2010) running costs and reliability

Item: Mazda RX-8 (2003 - 2010)
Rating: 2.5
Author: Richard Kilpatrick

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Running costs rating: 2.5 out of 52.5

Written by Richard Kilpatrick Updated: 20 September 2022

Miles per pound (mpp)

Reliable fuel consumption data for comparison purposes is not available for this model.

What is miles per pound?

Fuel economy

A more stringent standard for fuel economy (WLTP) was introduced from September 2017, and this model was not required to undergo that test. Its fuel economy measured under the previous test system was 24 - 26 mpg. However these figures are less likely to be achievable in real world driving and so should never be compared to another car's mpg which was measured under the newer, more realistic WLTP system.

View mpg & specs for any version

High fuel consumption
Rebuilds and reconditioning part of RX-8 ownership
Aftermarket upgrades worthwhile

Mazda RX-8 running costs

A used Mazda RX-8 can look pretty tempting, with so many for sale for less than £2,000. Buying the car is only the start, however. Claimed economy is around 26mpg, tax is high on 2006-on models, and insurance can be also high for many locations. We generally argue that the high tax is a small cost relative to everything else involved in running a performance car, but in the case of a bargain-basement and unreliable RX-8 it can add insult to injury.

Emissions range from 267g/km to 299g/km. As such, if you’re only tempted by an RX-8 because it’s a lot of car for not much money on Facebook, stick to pre-2006 models and ideally, the 192. If you want to do a lot of miles and enjoy the car, the R3’s improvements are worth paying for.

Mazda servicing is reasonable, the dealers are generally good, and RX-8s are long out of warranty. Parts supply is good, though as it’s over ten years since the car was last on sale that may begin to tail off.

Mazda RX-8 reliability

Used RX-8s have poor reputation, it’s deserved
Many cars for sale have problems
Most problems can be fixed

Mazda persevered with the rotary engine long after others gave up. Ever since it appeared in the 1960s, brave drivers tempted by the smooth, high-revving Wankel have discovered it just doesn’t have the robustness of a piston engine. Part of that is down to how accustomed to using and maintaining piston engines drivers are; there are cases of properly maintained Renesis engines reaching 200,000 miles, but most British examples are exhausted by 75,000.

This means that if you spot a non-running RX-8 for sale, even if you’re used to getting bargains with cheap fixes from other brands, the Mazda is probably going to cost money to fix. From spark plugs and coils, to overall wear, a failing RX-8 is a cascade of problems that many owners will make worse when trying to keep using an unhealthy car.

And the RX-8 is unusual here. Where many cars have reliability problems due to design or component failures, the RX-8 simply wears out. If you maintain it to a high standard it’ll take a long time, but sooner or later it will need a rebuild. If buying a mid-priced example, we’d recommend finding a specialist dealer who will provide a warranty.

Paying someone to diagnose RX-8 issues, particularly a garage that doesn’t know RX-8s well, will cost a lot of money and probably end in misery. Find a good specialist though the club, and follow their advice.

The good news is that engine wear and related problems aside, the rest of the RX-8 is quite dependable even as the cars approach 20 years old. £3,000 spent rebuilding the engine on a rust-free, non-running project for under £1,000 may be the best option in the long run.