Hi all,
The below information has been mostly cut and pasted from a thread I posted on LegacyGt.com and is for general informational purposes. Pablo on here was the primary driver behind my choice to go with AMSOIL 75w110 for my 08 Subaru Legacy GT 5-speed trans/front diff (they share).
This past week I ordered 5 quarts of AMSOIL 75w110 Severe Gear to do my trans and rear diff. I received it within 48 hours of ordering and I paid standard shipping.
I'm writing this post to provide information on why someone would choose to do this to their Legacy GT 5-speed or similar application.
Background for using this Fluid
Why AMSOIL? Why 75w110?
First, 75w110 is a new viscosity rating for fluids that were at the higher end of operating temperature viscosity 75w90. Here's a great link that shows the difference:
http://www.lubrizol.com/products/aut...r-oil/J306.asp
To sum-up....old 75w90 rating had a kinematic viscosity rating range at 100 degrees celcius from 13.5 - 24.0 (lower is less viscous). The new rating means 75w90 is between 13.5-18.0 and 75w110 is 18.0-24.0
So 75w110 is the equivalent of an old 75w90 that had a higher operating temperature viscosity....in AMSOIL's case, it's about ~20 on that range.
For those worried about cold viscosity....that range is for operating temperature. AMSOIL 75w110 has a lower cold pour point than Subaru Extra-S. It's actually more fluid at lower temperatures according to the viscosity ratings.
But that doesn't explain why AMSOIL? Well, I did this to help provide a benchmark for others. I'm a big fan of AMSOIL, having used it in my 06 Civic SI engine and trans to great benefit.
Many people have tried Subaru Extra-S, Uncle Scotty's Cocktail, and other fluids to help their Subaru transmission. A few people have tried AMSOIL 75w90 (bear in mind they have 3 different versions) with some good reviews and one or two poor reviews....but frequently the user didn't specify whether they used AMSOIL 75w90 long life, AMSOIL 75w90 severe gear (new), or AMSOIL 75w90 Manual Transmission & Transaxle Gear Lube. Each is a unique lubricant.
So I decided I wanted to risk my money on a newer lubricant, a full synthetic lube, a more viscous lube at operating temperature, a name brand not too often used in Subaru's (AMSOIL), and just provide a comparison point.
The Review
Let me be clear: Subaru Extra-S 75w90 set a high bar based upon reviews. People universally claim smoother shifting, no or less reverse lockout, good cold weather operation. So I had high expectations. I wanted AMSOIL Severe Gear 75w110 to remove gear/syncro whine, quiet the drivetrain down, allow me to comfortably shift much faster at mid-range rpm operation, remove some of the shifting notchiness/clunkiness, and remove most if not all times I would be locked out of reverse.
It's been about 200-250 miles and 4 days since I did the change. Unfortunately, I have nothing colder than 50 degrees to comment on, but I'll provide updates.
Reverse lockout is pretty much gone. I haven't experienced it yet. This morning, on the first shift (going into reverse) when the car was completely cold...it went into reverse with a really satisfying sensation and no notchiness or "pushing metal out of my way" resistance.
Overall shifting is smoother. It's no 06 Civic SI/Acura RSX Type-S/Honda S2000/Acura TSX shifter....but it's not going to be. But I no longer feel like I'm hurting my transmission....it feels much more natural and right. Slow shifting, fast shifting. It feels like the transmission doesn't mind anymore and it feels protected. It's hard to explain. AMSOIL claims the lubricant provides an "iron sulfide barrier" on the metal...it kinda feels like there is some protection on there.
The drivetrain is definitely quieted down. I don't know how to explain it exactly. The engine still sounds the same and has a little drivetrain lash upon sharper engine braking...but the trans whine/gear whine is pretty much non-existent.
Shifting at 4000+ rpms is much smoother and quicker. The gears engage faster. There is a split-second of syncro whine I can still feel/hear....but it's much LESS in noise and time spent hearing it.
At this point, I'm pretty happy. I wanted the transmission to feel "safe" from my everyday shifting, and it feels that way now. I won't worry about wearing out syncros anymore. Based upon reviews, i think Extra-S might smooth out the shifting a little more than I've experienced....but I can't really tell, now can I?
I would definitely support anyone choosing to go with this fluid at this time. I think winter (i.e. 10 degree) operation will be much more telling and I'll provide updates when that time comes. But for now, I'm satisfied.
I hope this post helps others in their choice. I think Subaru Extra-S is a great choice, especially now that the King of Parts sells it for $55 for 5 quarts. Personally, I'll probably try it in 40-50k miles. But I'd say Extra-S or AMSOIL 75w110 Severe Gear are both near equal cost gear lubricants, and while Extra-S offers alot more reviews with great satisfaction in shifting quality, AMSOIL probably provides a more robust lubricant to stand up to extreme stresses. So you really can't go wrong.
For BITOG: A big thank you to those who helped provid me with some guidance, especially Pablo.
Joe
The below information has been mostly cut and pasted from a thread I posted on LegacyGt.com and is for general informational purposes. Pablo on here was the primary driver behind my choice to go with AMSOIL 75w110 for my 08 Subaru Legacy GT 5-speed trans/front diff (they share).
This past week I ordered 5 quarts of AMSOIL 75w110 Severe Gear to do my trans and rear diff. I received it within 48 hours of ordering and I paid standard shipping.
I'm writing this post to provide information on why someone would choose to do this to their Legacy GT 5-speed or similar application.
Background for using this Fluid
Why AMSOIL? Why 75w110?
First, 75w110 is a new viscosity rating for fluids that were at the higher end of operating temperature viscosity 75w90. Here's a great link that shows the difference:
http://www.lubrizol.com/products/aut...r-oil/J306.asp
To sum-up....old 75w90 rating had a kinematic viscosity rating range at 100 degrees celcius from 13.5 - 24.0 (lower is less viscous). The new rating means 75w90 is between 13.5-18.0 and 75w110 is 18.0-24.0
So 75w110 is the equivalent of an old 75w90 that had a higher operating temperature viscosity....in AMSOIL's case, it's about ~20 on that range.
For those worried about cold viscosity....that range is for operating temperature. AMSOIL 75w110 has a lower cold pour point than Subaru Extra-S. It's actually more fluid at lower temperatures according to the viscosity ratings.
But that doesn't explain why AMSOIL? Well, I did this to help provide a benchmark for others. I'm a big fan of AMSOIL, having used it in my 06 Civic SI engine and trans to great benefit.
Many people have tried Subaru Extra-S, Uncle Scotty's Cocktail, and other fluids to help their Subaru transmission. A few people have tried AMSOIL 75w90 (bear in mind they have 3 different versions) with some good reviews and one or two poor reviews....but frequently the user didn't specify whether they used AMSOIL 75w90 long life, AMSOIL 75w90 severe gear (new), or AMSOIL 75w90 Manual Transmission & Transaxle Gear Lube. Each is a unique lubricant.
So I decided I wanted to risk my money on a newer lubricant, a full synthetic lube, a more viscous lube at operating temperature, a name brand not too often used in Subaru's (AMSOIL), and just provide a comparison point.
The Review
Let me be clear: Subaru Extra-S 75w90 set a high bar based upon reviews. People universally claim smoother shifting, no or less reverse lockout, good cold weather operation. So I had high expectations. I wanted AMSOIL Severe Gear 75w110 to remove gear/syncro whine, quiet the drivetrain down, allow me to comfortably shift much faster at mid-range rpm operation, remove some of the shifting notchiness/clunkiness, and remove most if not all times I would be locked out of reverse.
It's been about 200-250 miles and 4 days since I did the change. Unfortunately, I have nothing colder than 50 degrees to comment on, but I'll provide updates.
Reverse lockout is pretty much gone. I haven't experienced it yet. This morning, on the first shift (going into reverse) when the car was completely cold...it went into reverse with a really satisfying sensation and no notchiness or "pushing metal out of my way" resistance.
Overall shifting is smoother. It's no 06 Civic SI/Acura RSX Type-S/Honda S2000/Acura TSX shifter....but it's not going to be. But I no longer feel like I'm hurting my transmission....it feels much more natural and right. Slow shifting, fast shifting. It feels like the transmission doesn't mind anymore and it feels protected. It's hard to explain. AMSOIL claims the lubricant provides an "iron sulfide barrier" on the metal...it kinda feels like there is some protection on there.
The drivetrain is definitely quieted down. I don't know how to explain it exactly. The engine still sounds the same and has a little drivetrain lash upon sharper engine braking...but the trans whine/gear whine is pretty much non-existent.
Shifting at 4000+ rpms is much smoother and quicker. The gears engage faster. There is a split-second of syncro whine I can still feel/hear....but it's much LESS in noise and time spent hearing it.
At this point, I'm pretty happy. I wanted the transmission to feel "safe" from my everyday shifting, and it feels that way now. I won't worry about wearing out syncros anymore. Based upon reviews, i think Extra-S might smooth out the shifting a little more than I've experienced....but I can't really tell, now can I?
I would definitely support anyone choosing to go with this fluid at this time. I think winter (i.e. 10 degree) operation will be much more telling and I'll provide updates when that time comes. But for now, I'm satisfied.
I hope this post helps others in their choice. I think Subaru Extra-S is a great choice, especially now that the King of Parts sells it for $55 for 5 quarts. Personally, I'll probably try it in 40-50k miles. But I'd say Extra-S or AMSOIL 75w110 Severe Gear are both near equal cost gear lubricants, and while Extra-S offers alot more reviews with great satisfaction in shifting quality, AMSOIL probably provides a more robust lubricant to stand up to extreme stresses. So you really can't go wrong.
For BITOG: A big thank you to those who helped provid me with some guidance, especially Pablo.
Joe
