Red Line MT-90 is popular for owners with manual-transmission cars. Red Line MT-90 does not contain the reactive sulfurs found in most GL-5 oils that cause damage, so it’s safe for most manual transmission synchros. Other synthetic gear oils are often too slippery for proper synchro engagement, but MT-90 has the appropriate coefficient of friction, so it offers excellent gear and synchro protection, plus balanced slipperiness for easier shifting.
MT-90 is a 75W90 GL-4 gear oil recommended for use in manual transmissions on the track (excluding ’06+ Xi manual transmission). MT-90 is a thicker 75W90 version of MTL, and the shear stability and oxidation stability is excellent, so its characteristics change very little with use.
- Offers quicker shifts, perfect synchronizer coefficient of friction
- Eliminates notchy shifting
- High-performance gear protection and longer synchro life
- Recommended for GL-1, GL-3, and GL-4 applications as well as where most special synchromesh fluids are specified
TYPICAL PROPERTIES
| API Service Class | GL 4 |
| SAE Viscosity Grade (Motor Oil) | 15W40 |
| SAE Viscosity Grade (Gear Oil) | 75W90 |
| Vis @ 100°C, CSt | 15.6 |
| Vis @ 40°C, CSt | 90 |
| Viscosity Index | 185 |
| Pour Point, °C | -45 |
| Pour Point, °F | -49 |
| Brookfield Viscosity @ -40°C, Poise | 320 |
