After reading the numorous recommendations for Red Line manual tranny fluid, I've decided to try some on my 2003 4cyl Mazda6. It's a front-wheel drive family sedan with an open differential, and I autocross with it regularly.
When it came time to shop, I found Red Line makes a 75W90 and a 75W90NS oil. The "NS" oil seems to be intended for open differentials, I think, presumably because it does not have a friction modifier. I suppose an unfortunate side effect of reducing friction in the differential would allow it to spin very freely, and with an open differential would increase the probability of a one-wheel spin. That's no good! I'd rather the differential be tough to turn, but perhaps friction in the differential will create too much heat, causing problems of its own. Spinning the inside tire IS a problem for me autocrossing. While Red Line says both oils will work with open differentials, I think the 75W90NS sounds more appropriate.
Still, I wanted to get a 2nd opinion before I buy. I know a bunch here swear by Red Line tranny oil, but which type is it that ya'll are using. What are the trade-offs? Does it come down to personal preference? Is the friction modifier what makes shifting so much smoother, and would I forfeit that? Does one wear better? Does the friction modifier decrease drivetrain loss? Does that even matter?
Again, this isn't for a limited-slip RWD car, but an open-diff FWD car. I wouldn't be making a big deal out of this, but some of the other threads here seem to indicate that using the wrong friction modifier can be terrible.
[ January 05, 2004, 10:30 PM: Message edited by: Steve E ]
When it came time to shop, I found Red Line makes a 75W90 and a 75W90NS oil. The "NS" oil seems to be intended for open differentials, I think, presumably because it does not have a friction modifier. I suppose an unfortunate side effect of reducing friction in the differential would allow it to spin very freely, and with an open differential would increase the probability of a one-wheel spin. That's no good! I'd rather the differential be tough to turn, but perhaps friction in the differential will create too much heat, causing problems of its own. Spinning the inside tire IS a problem for me autocrossing. While Red Line says both oils will work with open differentials, I think the 75W90NS sounds more appropriate.
Still, I wanted to get a 2nd opinion before I buy. I know a bunch here swear by Red Line tranny oil, but which type is it that ya'll are using. What are the trade-offs? Does it come down to personal preference? Is the friction modifier what makes shifting so much smoother, and would I forfeit that? Does one wear better? Does the friction modifier decrease drivetrain loss? Does that even matter?
Again, this isn't for a limited-slip RWD car, but an open-diff FWD car. I wouldn't be making a big deal out of this, but some of the other threads here seem to indicate that using the wrong friction modifier can be terrible.
[ January 05, 2004, 10:30 PM: Message edited by: Steve E ]