The 2004 model year saw the introduction of the official turbocharged Mazdaspeed MX-5, Roadster Turbo in Japan. It featured an IHI RHF5 VJ35 turbocharger equipped variant of the BP-4W engine that produced 180 bhp (134 kW) at 6000 rpm with a front-mounted air-to-air intercooler. The MAZDASPEED could reach 60 mph (97 km/h) in 6.2 seconds but had a top speed of only 203 km/h (126 mph) due to its low 6,500 rev limiter.
With its upgraded suspension and wider tires, the Mazdaspeed model could pull over 0.98 g in lateral grip. Other features included upgraded 6-speed transmission and clutch assemblies, upgraded drivetrain components, Racing Hart 17 in (430 mm) alloy wheels, special interior trim. Perhaps the most obscure detail change of the MazdaSpeed overhaul of the MX-5 was the fitment of a custom, lightweight oil dipstick. The 2004 Mazdaspeed MX-5 was only available in Velocity Red Mica and Titanium Gray Metallic for the US-market and Velocity Red Mica for the Canadian-market while the 2005 model was available additionally in Lava Orange Mica and Black Mica in the US-market, with Canada receiving only Titanium Grey Mica. Of the 5,428 Mazdaspeed MX-5s produced during model years 2004 and 2005, 4,000 were produced in 2004; the 2005 production run was shortened to only 1428, due to a fire at the production facility. This model was also marketed in Australia as an MX-5 SE without any Mazdaspeed branding (exhaust tip excluded), featured 3.63 diff gears and was available in Sunlight Silver as well as Velocity Red Mica, Titanium Gray Metallic and Black Mica for 2005. It was also slightly detuned with only 121 kW (162 bhp). Boost pressure was 7.25 psi (0.5 bar) for Australian model vs 8.5 psi (0.6 bar) of the North American and Japanese models which is the main contributor to the power difference.
