As we celebrate the 35th Year of the MX-5, we take a look at the original car and assembly on the production line.

The MX-5 (Eunos Roadster or Miata) is an N-platform vehicle produced in mixed production* since the first generation in 1989, meaning it has been assembled together with other Mazda vehicles such as the Autozam, Demo to the current range of Sports CX SUV.

In the early days there was a surprising amount of manual processes involved which meant that and the finished car is truly a work of craftsmanship. It seems that about 260 staff members spent 3.3 hours assembling one car.

*Mazda’s mixed production

For more than 35 years, Mazda vehicles have been using a system called mixed production. Multiple vehicle models are assembled on a single production line and means that Mazda can manufacture products with flexibility, like having CX-5 or CX-80 lined up behind a MX-5.

To achieve this increased production efficiency, Mazda adopt a system in which the production order is determined in advance for each unit, suppliers and parts manufacturers deliver products in that order.

1. MX-5 Bodywork press line

The NA MX-5 mainly uses 0.7mm to 0.8mm steel plates, the presses created parts for 500 cars at once. The press machines at Mazda’s Ujina Plant (at the time) were made by Komatsu and IHI, and the parts that came out of the press were stored in racks and sent to the next line.

2. The welding line

On the welding line, parts brought from the press line are assembled and welded.
The welding time for one Roadster was approximately 8 minutes (during peak production, it reportedly took 4 minutes).
First, it is assembled by machine and temporary welding was performed.

3. Assembly of B type engine

Approximately 30 staff assembled 500 4-cylinder B-type engines a day. Of these, 27% were used in the MX-5. reportedly it took about 2 hours to assemble one engine. Assembling the connecting rod and piston and inserting them into the cylinder block is done by hand. After that auxiliary equipment such as the oil pan, flywheel, and water pump are installed. Adjustments were implemented on the test line.

Finally, the full powertrain, including the engine, transmission, and suspension, is assembled and sent to the assembly line.

4. The Assembly line

The completed body is painted on the welding line over a period of approximately 8 hours and sent to assembly where approximately 260 staff members spent 3.3 hours assembling an MX-5 on a line covering a length of 5,008 m.

The pre assembled power train is married to body, and the exterior panels such as the front and rear bumpers and wings are also added..

The wheels are added and the convertible hood is attached. Doors remain off at this stage to improve working space and access.

Next, interior items such as the dashboard and seats are added along with the windscreen.

The doors are then fitted and adjusted along with roof. Various electrical systems are then tested and the finally the car is tested for leaks.

The last thing to be added is the steering wheel. then off for final checks, adjustments to the suspension, wheel alignment and steering angles.
These final adjustments were unique to each car.

5. Dispatch and Delivery

The assembled car then makes it way to it’s new owner!

It is reported that around 20 NA MX-5 could be assembled each working day.

MX-5 Owners Club