Joined
·
1,631 Posts
I finally got around to swapping the oil in my manual transaxle with Red Line MT-85 75W-85 synthetic. The main reason was to hopefully reduce the stiffness on extremely cold winter days, so obviously we'll have to wait to see how that works out. But here are some initial impressions other than temperature-related ones.
Smoothness of Shifting
The transmission was pretty smooth before, but shifting is a bit smoother now. The throw between the gears, however, feels ... not exactly stiffer, and not harder to shift, but smoother and "dampened," if that makes any sense. It's hard to describe. It feels "not klunky" might be a better way to put it.
I'm not sure that's what I want. But I'm not sure that it's not. Again, the winter will tell.
Noise
The improvement here was unbelievable. I never thought the trans was especially noisy: It sounded like pretty much any other compact-car manual transaxle. But now it's like silent. There's no whine at all. The change is also a bit amusing because I realized that I was shifting later than I usually do. I'd been using the whine as an aural tachometer and shifting cue.
I'm not especially sensitive to noise. Between having spend so much of life in airports and airplanes, my hearing isn't what it used to be; and having spent even more time in rooms full of computers with their random whirrs, beeps, and other noises, I've also become more accustomed to ambient machine noises. But if you're noise-sensitive, then this gear oil is for you. The transmission is so quiet that I take the car out on the road just to listen to the now non-existent transmission noise.
MPG
It's much too soon to say what, if any effect this gear oil will have on MPG. I will say that I happened to fill up today at a Sunoco station about 26 miles away. Because of an extended downhill portion toward the end of the trip back from that station, the car's MPG readout (which is actually very accurate in my Soul) usually reads between 39 - 40 MPG when I get home after just filling up at that station. Today it read 38.
However, I also made some stops in town while I was there (and after filling the tank), I had more cargo in the trunk than usual, I'm still shifting later that I did before, and I was stuck behind a mope (from Ontario, of all places) who insisted on driving a good 15 MPH below the posted speeds.
As for the late shifts, I find myself getting as high as 3,500 to 4,000 on the tach before shifting, which is extremely rare for me unless I'm climbing a bufu steep mountain or intentionally blowing out some carbon. The transmission really is that quiet.
I don't expect any major effect on MPG. It's possible it will increase slightly, but it's also possible that it will decrease slightly. The oil is friction-modified to GL-4 standards to avoid brass synchro damage, so the usual benefits of increased lubricity of synthetic oil are nulled out by the intentional lubricity modification. So if the oil is coating the gears better (which certainly seems the case given the noise reduction), there might actually be a small decrease in MPG -- but more than offset by increased gear protection.
But it's really impossible to say what, if any effect the gear oil will have on MPG without running half a dozen or so tanks of gas through her. My average calculated and indicated MPG (they're rarely more than 1 MPG off from each other) using 89-octane with ethanol has been running about 36 - 37, by the way.
Miscellaneous Oddity
I mentioned that I've been shifting later, but it also seems like the car's upshift advice is occurring later. That could be my imagination, though.
All in all, I'm glad I made the swap, but the winter will be the real test. In the meantime, I can't help but think that the absence of whining means the gears and synchros are getting better lubrication; so that in itself makes the change worth it, in my opinion.
Smoothness of Shifting
The transmission was pretty smooth before, but shifting is a bit smoother now. The throw between the gears, however, feels ... not exactly stiffer, and not harder to shift, but smoother and "dampened," if that makes any sense. It's hard to describe. It feels "not klunky" might be a better way to put it.
I'm not sure that's what I want. But I'm not sure that it's not. Again, the winter will tell.
Noise
The improvement here was unbelievable. I never thought the trans was especially noisy: It sounded like pretty much any other compact-car manual transaxle. But now it's like silent. There's no whine at all. The change is also a bit amusing because I realized that I was shifting later than I usually do. I'd been using the whine as an aural tachometer and shifting cue.
I'm not especially sensitive to noise. Between having spend so much of life in airports and airplanes, my hearing isn't what it used to be; and having spent even more time in rooms full of computers with their random whirrs, beeps, and other noises, I've also become more accustomed to ambient machine noises. But if you're noise-sensitive, then this gear oil is for you. The transmission is so quiet that I take the car out on the road just to listen to the now non-existent transmission noise.
MPG
It's much too soon to say what, if any effect this gear oil will have on MPG. I will say that I happened to fill up today at a Sunoco station about 26 miles away. Because of an extended downhill portion toward the end of the trip back from that station, the car's MPG readout (which is actually very accurate in my Soul) usually reads between 39 - 40 MPG when I get home after just filling up at that station. Today it read 38.
However, I also made some stops in town while I was there (and after filling the tank), I had more cargo in the trunk than usual, I'm still shifting later that I did before, and I was stuck behind a mope (from Ontario, of all places) who insisted on driving a good 15 MPH below the posted speeds.
As for the late shifts, I find myself getting as high as 3,500 to 4,000 on the tach before shifting, which is extremely rare for me unless I'm climbing a bufu steep mountain or intentionally blowing out some carbon. The transmission really is that quiet.
I don't expect any major effect on MPG. It's possible it will increase slightly, but it's also possible that it will decrease slightly. The oil is friction-modified to GL-4 standards to avoid brass synchro damage, so the usual benefits of increased lubricity of synthetic oil are nulled out by the intentional lubricity modification. So if the oil is coating the gears better (which certainly seems the case given the noise reduction), there might actually be a small decrease in MPG -- but more than offset by increased gear protection.
But it's really impossible to say what, if any effect the gear oil will have on MPG without running half a dozen or so tanks of gas through her. My average calculated and indicated MPG (they're rarely more than 1 MPG off from each other) using 89-octane with ethanol has been running about 36 - 37, by the way.
Miscellaneous Oddity
I mentioned that I've been shifting later, but it also seems like the car's upshift advice is occurring later. That could be my imagination, though.
All in all, I'm glad I made the swap, but the winter will be the real test. In the meantime, I can't help but think that the absence of whining means the gears and synchros are getting better lubrication; so that in itself makes the change worth it, in my opinion.
