Fluids

All fluids listed on this page exceed the suggested manufacturer's specifications for use in a 1991 BMW 318is, and are considered the appropriate fluids for track and race among many E30 race car owners. Track and race car fluids should be changed much more regularly than street-use cars, as often as every three or four track weekends.

Transmission Fluid

Redline D4 ATF

Replacement Interval: 4 track weekends

Toronto Supplier: Garage 16

To increase the life of the many gears in the transmission, and to improve shifting smoothness, I change transmission fluid every fourth track weekend. If I miss several high-speed shifts, or "grind the gears," I change the fluid immediately and inspect the fluid for metal shards that might have broken off the gears. Changing the fluid ensures that no such shards remain in the transmission, where they could further damage the gears.

Differential Fluid

Redline 75W90

Replacement Interval: season start, then 8 track weekends

Toronto Supplier: Garage 16 (special order. make it clear you do not mean MT90.)

I change differential fluid at the beginning of every season, and every time I change my differential.

Brake Fluid

ATE DOT 4 Super Blue Racing or ATE DOT 4 Typ 200

Replacement Interval: 4 track weekends

Toronto Supplier: WunderKar

"Super Blue Racing" and "Typ 200" are identical fluids in different colours (blue and gold, respectively), allowing for easy differentiation between old and new fluids during brake fluid replacement. Bleed the old fluid until the new fluid colour appears at each caliper.

I change my brake fluid every fourth track weekend. When bled correctly, fresh fluid gives a firm brake pedal and prevents "brake fade." Brake fade is softness in the brake pedal caused when brake fluid boils, introducing air bubbles into the hydraulic brake system, particularly in the brake calipers.

Engine Oil