Why is it an STi

In the UK we have a range of models for the Subaru Impreza, top of which is the Turbo 2000 (forgetting any limited editions such as the Series McRae - 1995, Catalunya - 1996, Terzo - 1997, RB5 - 1998). This car produces around 218 ps.
In Japan, home of Subaru Impreza, the standard model is known as the WRX. Most of the current 2 and 4 door models produce 280 PS (276 BHP), only on Japanese 100 RON super unleaded fuel. Acceleration times are close to 5 seconds for the 0-62 sprint, however top speeds are limited by Japanese law to 112 mph.

What's an STi ?

A STi is a standard WRX which has, in theory anyway ;-) visited Subaru Tecnica International, the, now famous rally arm of Subaru. They have also released a number of limited edition models such as the V-Limited range and the 22B-STi wide bodied Coupe. Our 555 Limited edition was produced to replicate the World Rally Championship car of that year
The engine benefits from a few tweaks such as being manufactured and assembled to higher tolerances (blueprinting) with some stronger items being used.
The gear box has slightly shorter ratios and a quick shift come as standard.
A different ECU, water spray intercooler, inlet manifold and exhaust allow the engine to produce a slight increase in torque over the WRX although maximum power remains the same (275 Ps on our model).
Suspension is uprated and the arms are replaced by alloy items, and a strut brace is added in the engine bay.
Externally the car is badged by a pink STi logo on the front grill. The ,pointless, fog lights are also dropped in favour of two covers with large STi logos, the rear wing is larger, on the roof is a rally style air intake, and the Bonnet is an alloy item.

Who's Subaru Tecnica International ?

Subaru Tecnica International (STi) was founded in April 1988 by Fuji Heavy Industries producers of Subaru cars. Its aim was to promote Subaru products in its markets around the world using the motorsport arena. STi identified international rallying and endurance speed records as two areas to increase Subaru's presence in the motorsport world.
The newly launched Legacy set two world records and 13 international records in attempting the 100,000km FIA World Speed Record in January 1989. The World Rally Championship project evolved from Subaru's involvement in Japanese rallying but became a full scale factory effort when STi joined forces with the British-based Prodrive company. The initial objective was to pose a serious challenge to the established manufacturers competing in the World Rally Championship.
With the Prodrive engineered and run Legacy now a rally winner in the World Rally Championship and throughout the world and the successful debut of the new Subaru Impreza 555, STi is ensuring a high profile for the Subaru products on the world stage.

In addition to the higher profile motorsport has given Subaru in its markets throughout the world, it has also demonstrated the level of design and technology inherent to Subaru products. Many of the lessons leant in competing in the World Rally Championship are incorporated into the design of production models, benefiting all Subaru drivers.