Gearing is an overlooked and often poorly understood part of tuning. For those of you already not well versed in tuning concepts, the choice of gear ratios in the transmission can have as much to do with the character of the car as the actual power output of the engine. (Well, within reason anyway!) Differences of 2-4 percent in ratios will alter both the feel and acceleration ability of any car. This is because the torque multiplication of the engine power is a product of the overall ratio (gear ratio times final drive ratio) of each gear. This the area we examine in this section. We will only discuss the WRX 5-speed in this section. 5-speed options and the STI six-speed will have its own sections later.

To me the most disappointing fact about the world market WRX is the very tall gearing we share with the 5-door version of the WRX NB turbo in Japan. The taller, wider ratio gear box has a near useless fifth gear. Changing to a closer ratio gearbox that has closer 3rd, 4th and 5th would magically improve mid to high speed acceleration off of corners. It would also limit your desire to wind the motor out all the time in the intermediate gears and better utilize the mid range torque the motor effortlessly produces. Yes, the car would run down the freeway at higher rpm, but it is a trade I will take any day, six speed gearbox not withstanding. In fact, Australia is getting the shorter geared Japan gearbox for 2003 at the request of the importer.

Many would argue that the taller gears reflect the turbo motor's broad torque band or that taller gears let the turbocharger spool up fully. Let's put it this way: Although the Japan five-door version has always had tall gearing, the Japan 4-door WRX continues to enjoy the same basic ratios it had when first introduced in 1993. My own car has this 1993-96 gear box with shorter 3rd, 4th and 5th gears. I enjoy it and do not mind running the motor between 3400 and 4000 RPM on the open road. After 120,000 miles the motor does not seem to have minded either.

A more reasonable and convenient excuse for European WRX models to have a tall set of gears is the high speeds seen still seen on the Autobahn and to a lesser extent in England, because you can get busted for over 100 mph on the motorway. Or, we might claim that an 'average' American consumer would also be alarmed at 3500 rpm plus engine speeds on cruise control. Both are in fact true reasons for selling a wide ratio gearbox outside of Japan, but in reality our EPA gas mileage test cycle has long favored a very tall 5th gear to get the fuel mileage as high as it possibly can. There is wide ratio and then there is w-i-d-e ratio. We have the w-i-d-e ratio.

The Japan WRX NB turbo 4-door gets the same, closer geared, let us say "middle close", 4.44 final drive transmission of the earlier 1999-2000 WRX models. Examine the chart just below. Engine speed are the horizontal lines, MPH speed reads across the bottom. The red and black diagnal lines are 1st-5t gears. Two sets of ratios are overlaid on each other. Red is Japan close ratio, Black is the US WRX (and Japan five door).

Vehicle speed at each red line 7,000 rpm engine speed is read at the bottom of the chart. The graphs immediately show how different driving a Japan specification WRX is going to be. Second, third and particularly fourth gear pull much better and the fifth gear can do 'point and squirt' lane changes not unlike our 4th gear does now. When the Japanese WRX shifts to third at 60mph it starts pulling from 5000 rpm, the world gearbox is pulling from only 4600rpm. Huge difference in power to the wheels and the Japan model is going to just walk away. With the pulling power of fourth gear a Japan WRX is going to run away and hide. Going 6000 rpm in 5th at 120 mph? No problem! 

Japan WRX 4-door is red lines, export gearing is in black. 

It is hard to describe how much the shorter gearing of the Japanese version the character of the car. You would not believe how much more pick up the Japanese car has just by looking at a graph. 

Note the difference in the graph for the 3rd, 4th and 5th rpm at 75 mph. This is a huge difference in the torque multiplication of the engine power at higher road speeds. Notice the row of colored dots across the 3500 rpm line of the graph. These represent the 'return' RPM after each gear change. The Japan WRX can be just rowed with the gearbox in the mid torque range of the engine from 30 to 75 mph never going much above 5000 rpm. Now notice the black set of dots as they fall away from the colored dots. This means the US car turns lower and lower RPM if shifted at the same road speed of the Japan WRX. In contrast, the Japan gearbox ratios keep the motor in the sweet spot, while the US ratios just fall away at normal road speeds. When driven with moderate RPM, say between 3500 and 5000 rpm, the US car becomes very sluggish above about 60 miles per hour in comparison to the close geared WRX. The Japanese WRX will pull very strong between corners to about 100 mph without ever going above 5500 rpm! This is what is meant by gear ratios affecting the car's character. Not only is the Japanese set of gear ratios much sweeter to drive in the intermediate speeds, the US car basically has nothing left to it after the red line in 3rd gear when compared to the acceleration ability if the Japan gearbox. 

This closer geared transmission is perhaps the most substantial difference between the Japan WRX and the world export models, certainly as important as the difference in power.