Mazda RX-7 | Used Car Buying Guide

Few cars are as defined by their powertrain as much as the Mazda RX-7.

Steadfastly bucking the trend for conventional internal combustion engines, Mazda stuck with its Wankel rotary set-up for its RX-7 sports car. Specifically, a twin rotary engine, with a combined capacity of 1.3-litres, its 237bhp output assisted by a pair of turbos.

The advantages are obvious; you only have to look at the RX-7’s low nose to see that Mazda’s rotary unit is compact, its positioning low and far back under that gloriously sculpted bonnet also helping the RX-7 gain serious praise for its handling.

Praise highlighted on these pages, Autocar’s original test of the RX-7 in July 1992 not short of admiration for the RX-7, comparing it favourably to that contemporary paragon of handling and performance: the Porsche’s 968.

Despite this the Mazda never sold particularly well, not least because its price put it within a few hundred pounds of that Porsche. Its might have offered a specification advantage over the 968, but Mazda’s badge lacked prestige in comparison to that on the Stuttgart machine.

Mazda did undertake a couple of price drops on the RX-7 to try to increase sales - the list price eventually dropping from £34,000 to a touch over £26,000 - but the RX-7 remained a bit-part player in a busy sports car marketplace in the early 1990s.

Its oddball mechanical specification certainly didn’t help its cause. For all Mazda’s perseverance with the rotary engine Wankel’s powerplant has never had the best reputation for reliability. Or thirst. That prodigious drinking habit was outlined in Autocar’s test, the RX-7 managing a less than impressive 15.5mpg overall figure.

By comparison the contemporary Ferrari 512 TR managed 14.7mpg. Reliability would take a while to rear its head, but the RX-7 hasn’t exactly covered itself in glory, the twin-rotary unit not exactly a byword for trouble-free motoring.

Yet, looked after correctly the RX-7 can be an enjoyable ownership proposition, and with prices starting at around £5000 it’s a lot of good-looking, high performance and fine handling sports car for the money.

The first arrived in 1992, Mazda UK having no official record of how many it brought in, but it’s in the hundreds. Unsurprisingly it stopped officially being imported in 1996 - making UK specification cars relatively rare.

Official UK RX-7s sat somewhere between the various offerings Mazda delivered in its home and USA/Australian markets, UK cars doing without the occasional rear seats, gaining air conditioning and adding a second catalytic convertor to the exhaust.

All are described as FD series cars, though with Mazda producing the RX-7 right up until 2002 in Japan a number of updates were made in its lifecycle. The various models include the R, RS, RZ RB, A-Spec and Touring, all but that Touring coming with a five-speed manual, it featuring a four-speed auto.

The closest import model to UK specification is the RS. Some special editions were also built, the Bathurst having 274bhp. Further confusing things is Mazda’s use of its Efini sporting brand in Japan, with many making it over to the UK so badged.

Always a relatively rare sight with the original cars over 20 years old the RX-7 is even more so now. They’ve got something of a cult following today, which has seen prices bottom out and start to rise again for the very best.

Gary Marks, owner of Mazda rotary specialist RoTechniks, 01189 888 555, www.rotechniks.co.uk has owned several and worked on countless others, and knows their foibles.

Most, unsurprisingly centre around that unique engine, but Marks says with proper care and attention they’re not the nightmare they’re made out to be. Most issues arise from misuse, the RX-7 needing a heat cycle through it before using all those revs. Don’t do that and you’ll have issues with the water seals, which is an engine out and rebuild job. To do so will cost you £3300, though RoTechniks offers a choice of warranties with that.

Servicing should be every 6000 miles/annually according to Mazda’s schedule, Marks preferring to use semi-synthetic or fully synthetic oil over the pure mineral oil that Mazda specified. Modern oils are better at dealing with the heat the Wankel unit generates. Marks suggests a 3000 mile oil change, selling a kit to do so for just £30.

The 6000 mile service costs £140, a larger 12000 mile service £180 and a 24000 mile service £260-280. Given the heat and those seals Marks also recommends waterless coolant, which makes the system pressureless, helping preserve the engine seals and hoses.

The simplest check on the health of the engine is to test the compression. Marks says the hot compression should be 7 to 9 kilos per cm, with anything below 5 meaning you’ll be needing a rebuild. If it’s troublesome starting from hot then it’s likely to be low. Most require some sort of major engine work at around the 80-90,000 mile mark, many taking the opportunity to modify the engine for more power.

There are lots of options to do so, Rotechniks is able to port the engine to suit differing turbos, it relatively easy to get a reliable 400bhp. The turbos will cost around £2000 on top of the engine work. Many have dropped the twin turbo set up for a single one, and if it’s small enough it shouldn’t affect driveability.

Bigger single turbo set ups can produce big numbers, but they’ll come with laggy response. More power will require a tougher clutch, Marks rating Carbonetics set ups, these available with single, double or triple plate, Carbonetics also offering a replacement limited slip differential.

The stock transmission and suspension are difficult to fault, though with 32 different bushes underneath Marks says to bank on changing at least one or two every service. The brakes should provide great service too, though Marks says they’ll need regular cleaning to help prevent binding - as you’d expect on a car of this age.

The bodywork wears well, though beware of damage or rot under bodykits and wings, a common upgrade being to fit later 1999 specification front bumpers and rear lights - featuring three circular lights each side of the distinctive housing.

Rotechniks will look over any prospective purchase for around £100, which given its unique specification would be a wise investment. Find a good one though and the RX-7 should thrill like little else, that smooth rotary power a unique and enjoyable experience. So much more interesting than its contemporaries too, so long as you’ve the time and money to invest in it:

Mazda RX-7 problems:

Engine:

The RX-7’s twin rotary engine features two turbos to produce 237bhp in UK specification. Japanese cars produced more, between 265-285bhp thanks to the loss of one of the cats in the exhaust. The engine is complex, it unlikely you’ll find one that’s not been rebuilt at some point. Expect to do so at around 80,000 miles, at a cost of around £3300.   

Transmission:

Standard manual transmission is strong, it able to manage up to 500bhp without any modifications. A clutch will cost you around £600 and it’s essential you change the needle bearing at the same time for a crisp shift. If you are modifying the engine it’s worth adding an upgraded one, with kits available from about £1500. 

Chassis:

The suspension is tough, though with 32 different bushes underneath it’ll be a rare service where you’re not having at least one done. The standard Mazda bushes are best, while Feed in Japan do a full kit of bushes and bearings for around £1200. Many add a coilover kit for track use. Doing so will cost around £1200.

Brakes:

No real issues with the strong standard brakes, though if track use is intended then a set of uprated pads will help. It’s worth stripping the brakes and cleaning them completely when changing pads to help prevent age-related binding. Plenty of upgrades are possible, but the standard brakes are more than up to the task for road use. 

Cabin:

The cabin is fairly plain, UK cars featuring a pair of covered luggage lockers in the back, Japanese cars coming with seats. Door window switches are prone to breaking and are getting tougher to find, and seat bolsters on the driver’s side collapse with age and use. Otherwise it should be fairly robust, if unremarkable to look at.

Wheels, Tyres and Bodywork:

Standard wheels are 16-inches, though it’s unlikely you’ll find any still so equipped. Bigger than 17-in ruins the ride. Rust around the rear wheel arches is not unusual, particularly on older UK cars though not exclusively. Japanese imports have less rustproofing so it’s worth having it waxoiled to prevent any problems.

What to look out for:

Engine rebuilds and RX-7s are an inevitability, check when it was done and by whom, a full rebuild costing in the region of £3300 - it should come with a warranty, too. 

Check the front passenger footwell carpets for dampness. If they are it’s likely to be the heater matrix, which is a dash-out job to fix. If the £600 ECU gets wet it’ll run rough, if at all.

Regular, specialist servicing is essential to keep the RX-7’s engine in tip-top condition. The oil should be changed every 3000 miles with a good-quality semi synthetic and have it compression tested regularly.

Water leaks in the engine mean an expensive rebuild, it’s tricky to tell if it is leaking though a tip is to smell the exhaust, if it’s sweet then there’s coolant getting into the engine.

Start the car from both hot and cold. If it struggles to hot start it’s likely to be compression. Any smoke points to either worn turbos or oil control rings.

Quoted prices correct at time of publication.

To search for a used Mazda RX-7 for sale on PistonHeads, click here.

Kyle Fortune