Is there any reason to run the 75w110 Amsoil Severe Gear over the 75w90 Amsoil Severe Gear in a daily driver Subaru Forester that sees very hot and very cold temps here in Ohio?
Amsoil Severe Gear 75w90 vs 75w110
- Thread starter Cooper
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JHZR2
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No. What does the OM spec?
Probably not. Unless you are racing it.
The OM specs GL-5. You can use various weights.....
The cold temp spec is the same on both, and the amsoil high pressure lube hangs onto the ring gear teeth very very well as the pinion teeth sweeps over them, as others said, if you aren't either key word 'frequently taking track days, pulling around car loads of people ALL the time, then I wouldn't want the thicker stuff, it's just more drag to overcome, and less torque to the wheels. Heavier gear oils are really made for heavy duty trucks where the pinion gear will exert very large amounts of torque on the ring gear under towing conditions, where the lighter oil just can't "hang on" to the teeth as the pinion sweeps over them, absolutely not a concern in a light vehicle.
-srv
-srv
I was planning on purchasing the 75w90 at first, but wasn't sure if there was any reason to go with the heavier weight....
I ordered the 75w90.
I ordered the 75w90.
JHZR2
Staff member
Remember that years ago, the API cut apart the "90" spec to be the lighter end of the original range. By now the spec writers could have mandated something else - some have. If they are saying 90wt in there, or thats what Subaru sells under the part number for the lube, that's the viscosity Id use with confidence, especially with a high end lube like that.
That aint no sti
Originally Posted By: ChemicallyChargd
The cold temp spec is the same on both, and the amsoil high pressure lube hangs onto the ring gear teeth very very well as the pinion teeth sweeps over them, as others said, if you aren't either key word 'frequently taking track days, pulling around car loads of people ALL the time, then I wouldn't want the thicker stuff, it's just more drag to overcome, and less torque to the wheels. Heavier gear oils are really made for heavy duty trucks where the pinion gear will exert very large amounts of torque on the ring gear under towing conditions, where the lighter oil just can't "hang on" to the teeth as the pinion sweeps over them, absolutely not a concern in a light vehicle.
-srv
Correct info above on the use of heavier differential fluid for more towing and higher torque situations. Also, gear oils are designed to work chemically on the iron to prevent scuffing, pitting, and galling, even when there is no lubricant film present. The GL-5 gear oils produce a chemical layer of iron sulfide on gears, which is sheared off when there is metal-metal contact. This prevents straight iron-iron contact that produces scuffs, cold welding, and other very very bad things.
The cold temp spec is the same on both, and the amsoil high pressure lube hangs onto the ring gear teeth very very well as the pinion teeth sweeps over them, as others said, if you aren't either key word 'frequently taking track days, pulling around car loads of people ALL the time, then I wouldn't want the thicker stuff, it's just more drag to overcome, and less torque to the wheels. Heavier gear oils are really made for heavy duty trucks where the pinion gear will exert very large amounts of torque on the ring gear under towing conditions, where the lighter oil just can't "hang on" to the teeth as the pinion sweeps over them, absolutely not a concern in a light vehicle.
-srv
Correct info above on the use of heavier differential fluid for more towing and higher torque situations. Also, gear oils are designed to work chemically on the iron to prevent scuffing, pitting, and galling, even when there is no lubricant film present. The GL-5 gear oils produce a chemical layer of iron sulfide on gears, which is sheared off when there is metal-metal contact. This prevents straight iron-iron contact that produces scuffs, cold welding, and other very very bad things.
Originally Posted By: 147_Grain
After a 5K break-in period of the front and rear differentials on my 2013 Subaru Outback, I replaced the fluid with Amsoil's 75W-90 Severe Gear Oil and am pleased with the results.
Which were?
After a 5K break-in period of the front and rear differentials on my 2013 Subaru Outback, I replaced the fluid with Amsoil's 75W-90 Severe Gear Oil and am pleased with the results.
Which were?
Originally Posted By: ChemicallyChargd
The cold temp spec is the same on both ...
Incorrect. The SVT (75w110) is heavier at all temperatures (~30-50%) compared to the SVG (75w90).
I've used the SVG in the front and rear diffs in an 02 Forester and am pleased all around. Better protection and economy compared to the stock 80w90 fluids used. If I change it again I might opt for Motul Gear 300 but that's splitting hairs.
Bottom line is the SVG is a fantastic fluid an unless you're overheating the diff(s) you won't need anything 'better'.
The cold temp spec is the same on both ...
Incorrect. The SVT (75w110) is heavier at all temperatures (~30-50%) compared to the SVG (75w90).
I've used the SVG in the front and rear diffs in an 02 Forester and am pleased all around. Better protection and economy compared to the stock 80w90 fluids used. If I change it again I might opt for Motul Gear 300 but that's splitting hairs.
Bottom line is the SVG is a fantastic fluid an unless you're overheating the diff(s) you won't need anything 'better'.
With gear oil I go as thin as possible. It reduces drag. However if towing or significantly elevating the rear end temps its time to consider something thicker.
I'm a big fan of redline. Its basically shear proof and we are all awake of how over the top redline formulates their fluids.
Of the 2 options I'd use the thinner one if no towing or routinely pounding on it.
I like shockproof light in everything I own with shockproof heavy going in the rear diff of my 4x4's.
Jim Allen is the man when it comes to this stuff though. Try to get his opinion.
The guy has temp gauges in his front and rear diffs. That says it all.
Pm him if necessary
I'm a big fan of redline. Its basically shear proof and we are all awake of how over the top redline formulates their fluids.
Of the 2 options I'd use the thinner one if no towing or routinely pounding on it.
I like shockproof light in everything I own with shockproof heavy going in the rear diff of my 4x4's.
Jim Allen is the man when it comes to this stuff though. Try to get his opinion.
The guy has temp gauges in his front and rear diffs. That says it all.
Pm him if necessary
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Here are some links for comparison on the fluid specs:
Spec -- Motul / SVG / SVT
ViscInd -- 222 / 167 / 171
KV100 -- 15.2 / 16.8 / 21.3
KV 40 -- 72.6 / 109 / 146
BV-40 -- ???? / 70.4 / 95.5
PourP -- -60 / -48 / -46
Motul Gear 300 75w90
http://www.motul.com/system/product_desc...%2075W90_GB.pdf
Amsoil SVG
http://www.amsoil.com/shop/by-product/gear-lube/severe-gear-75w-90/
Amsoil SVT
http://www.amsoil.com/shop/by-product/gear-lube/severe-gear-75w-110/
Spec -- Motul / SVG / SVT
ViscInd -- 222 / 167 / 171
KV100 -- 15.2 / 16.8 / 21.3
KV 40 -- 72.6 / 109 / 146
BV-40 -- ???? / 70.4 / 95.5
PourP -- -60 / -48 / -46
Motul Gear 300 75w90
http://www.motul.com/system/product_desc...%2075W90_GB.pdf
Amsoil SVG
http://www.amsoil.com/shop/by-product/gear-lube/severe-gear-75w-90/
Amsoil SVT
http://www.amsoil.com/shop/by-product/gear-lube/severe-gear-75w-110/
Finally got around to changing the diff fluid in the front and the rear of the Forester. Amsoil Severe Gear 75w90 went in the front and the rear. I did find that the front diff is a completely new diff for the 2014 Forester compared to other Subarus. The rear diff appears the same but used 2 10mm hex instead of 13mm square plugs. The Amsoil feels great. Nice and smooth. I did notice a slight shudder at slow speed uphill acceleration from stop with the OEM diff fluid, that is gone.
The OEM fluid in the rear looked dark and black with a lot of metal "sludge" on the magnet. The front wasn't as bad. The Forester has 15k miles on it.
I will continue to use Amsoil Severe Gear 75w90 for the life of the diffs if I don't have any problems. I plan on changing them out every 30k miles.
The OEM fluid in the rear looked dark and black with a lot of metal "sludge" on the magnet. The front wasn't as bad. The Forester has 15k miles on it.
I will continue to use Amsoil Severe Gear 75w90 for the life of the diffs if I don't have any problems. I plan on changing them out every 30k miles.
Amsoil Severe Gear 75W90 will serve you well and your investment. Great vehicle and amazing product to protect the vehicle.
I wouldn't put anything other than Amsoil in my gears -- btw I have 75W110 on my highlander and it has close to 80K and smooth and predictable!!!
I wouldn't put anything other than Amsoil in my gears -- btw I have 75W110 on my highlander and it has close to 80K and smooth and predictable!!!
Originally Posted By: Cooper
I will continue to use Amsoil Severe Gear 75w90 for the life of the diffs if I don't have any problems. I plan on changing them out every 30k miles.
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Your aggressive PM is unnecessary, the manufacturer says 100K, why do it at 30k, that is what the pundits in the forum keep telling. There is nothing other than metal out in the x-case and diff, no sensors nothing etc requiring replacement, a little gunk over 100K is not going to kill these purely mechanical hardware. Your aggressive PM is definitely making Amsoil quite happy!!
I will continue to use Amsoil Severe Gear 75w90 for the life of the diffs if I don't have any problems. I plan on changing them out every 30k miles.
\
Your aggressive PM is unnecessary, the manufacturer says 100K, why do it at 30k, that is what the pundits in the forum keep telling. There is nothing other than metal out in the x-case and diff, no sensors nothing etc requiring replacement, a little gunk over 100K is not going to kill these purely mechanical hardware. Your aggressive PM is definitely making Amsoil quite happy!!
MolaKule
Staff member
Quote:
Your aggressive PM is definitely making Amsoil quite happy!!
True, but aren't we all somewhat obsessive about lubricants here?
Your aggressive PM is definitely making Amsoil quite happy!!
True, but aren't we all somewhat obsessive about lubricants here?
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