Amsoil Diff Fluid
05-06-2015, 12:20 AM
#1
Registered User
Thread Starter
Amsoil Diff Fluid
Not intending to get hyper technical here or in the weeds...
Had some axle work done at my local mechanic and he refilled by diff w/ whatever standard diff fluid the shop stocks... I've been driving around for about 2 months now with that fluid in.
Well, I changed fluid this weekend back to Amsoil Severe Gear Gear Oil 75w90 (what I had in before the work -- finally got around to ordering it and replacing), and I'd say it seems like I have an extra ~20 extra hp on startup (before diff warmed up) and ~10 hp the rest of the time... Mainly feel it in throttle responsiveness and acceleration, but it's very real -- wasn't looking for a difference, just have taken such notice of "wow" the past couple days I wanted to comment. Here's the link: http://www.amsoil.com/shop/by-produc...e-gear-75w-90/
They have a great gear oil study too comparing their product to others (bottom line, royal purple or lucas synthetic gear oils look like a really bad idea): http://www.lastgreatroadtrip.com/wp-...comparison.pdf
Once I have a few weeks worth of mileage to compare, I'll post back here w/ those results, but it will definitely be a significant increase, especially since I run a lot of short trips... If you're looking for an immediate impact on improved performance, here's one quick an easy upgrade.
Also, I run gold plug drain plugs on my front and rear diff drain plugs as well... their bolt heads are of harder metal, but did require a thinner walled socket on the front to install that one (the silver sockets rather than parkerized and thicker impact wrench ones). I'd say magnets are 3 to 5x stronger on the gold plugs than stock OE magnetic drain plugs. For fill I also just replaced one with new OE, but realized I goofed -- I should have used a magnetic allen key bolt (drain plug part # for transfer case on mine at least) there rather than another soft headed OE bolt... (And then don't forget to install extended diff breathers -- it's a vacuum connection part # 9040451319 w/ same threading -- forget if 3/8 or 1/4 inch hose offhand, but it's one or the other... I believe I have the following needs for extended breathers on my truck, 5 total, but have only done the diffs to date as they sit the lowest -- front and rear diffs, transmission a340h, transfer case extension/hydraulic part that shares fluid w/ the tranny, and then transfer chain case.)
Had some axle work done at my local mechanic and he refilled by diff w/ whatever standard diff fluid the shop stocks... I've been driving around for about 2 months now with that fluid in.
Well, I changed fluid this weekend back to Amsoil Severe Gear Gear Oil 75w90 (what I had in before the work -- finally got around to ordering it and replacing), and I'd say it seems like I have an extra ~20 extra hp on startup (before diff warmed up) and ~10 hp the rest of the time... Mainly feel it in throttle responsiveness and acceleration, but it's very real -- wasn't looking for a difference, just have taken such notice of "wow" the past couple days I wanted to comment. Here's the link: http://www.amsoil.com/shop/by-produc...e-gear-75w-90/
They have a great gear oil study too comparing their product to others (bottom line, royal purple or lucas synthetic gear oils look like a really bad idea): http://www.lastgreatroadtrip.com/wp-...comparison.pdf
Once I have a few weeks worth of mileage to compare, I'll post back here w/ those results, but it will definitely be a significant increase, especially since I run a lot of short trips... If you're looking for an immediate impact on improved performance, here's one quick an easy upgrade.
Also, I run gold plug drain plugs on my front and rear diff drain plugs as well... their bolt heads are of harder metal, but did require a thinner walled socket on the front to install that one (the silver sockets rather than parkerized and thicker impact wrench ones). I'd say magnets are 3 to 5x stronger on the gold plugs than stock OE magnetic drain plugs. For fill I also just replaced one with new OE, but realized I goofed -- I should have used a magnetic allen key bolt (drain plug part # for transfer case on mine at least) there rather than another soft headed OE bolt... (And then don't forget to install extended diff breathers -- it's a vacuum connection part # 9040451319 w/ same threading -- forget if 3/8 or 1/4 inch hose offhand, but it's one or the other... I believe I have the following needs for extended breathers on my truck, 5 total, but have only done the diffs to date as they sit the lowest -- front and rear diffs, transmission a340h, transfer case extension/hydraulic part that shares fluid w/ the tranny, and then transfer chain case.)
Last edited by RSR; 05-06-2015 at 12:25 AM.
05-09-2015, 03:39 PM
#2
If you're switching from a standard mineral oil 90 weight then the difference you're feeling is probably real. If memory serves 90wt gear oil at room temp can be 10x more viscous than a full synth 75w-90. But at service temp (100C) they are about the same.
Could also be feeling the difference between new and broken in bearings?
Could also be feeling the difference between new and broken in bearings?
05-11-2015, 02:06 AM
#5
Registered User
Thread Starter
No new bearings or gear in the diff... Just ended up having them do a rear diff to axle seal and a carrier bearing. Thought I was having a U joint go (weird high pitch squeak at low speed) and wanted them to diagnose and replace them all if needed... Seal needed done regardless.
Couldn't figure out the squeak (apparently beyond the old mechanic's hearing range) but we worked up a sizeable bill on it... I hosed down my rear leafs with WD40 and the shackles w/ silicone spray and haven't heard it come back...
Regardless, mileage: In the month or so I had that standard gear oil in (I'm sure it was OE spec, which would be 75w90 I think -- these guys are by the book which I appreciate and late 50s/early 60s, two old toyota techs still working for themselves).
Last two fillups have been more highway than city and pretty close driving conditions, but I do a lot of mixed city/highway driving and work from home so don't have a standard commute, just a standard routine...
Tank with the dino rear diff gear oil was 12.36 mpg.
Latest tank with the amsoil 75w90 severe gear oil was 13.44 mpg.
I've been averaging right around 12.3 mpgs w/ the dino oil -- best tank in over a month of driving was 13.38 and worst was 11.10. With amsoil in the rear diff in the past I've hit 17.5 mpgs w/ purely highway driving, mid 14s with mixed city/highway but highway heavy, and generally see high 11 to low 12 mpg as my low end standard.
So I'd say, it's a pretty solid 1/2 to 1 1/2 mpg gain w/ that fluid for me and my truck. With a 1 mpg gain being the likeliest assumption at this point. Will post more numbers at the next two fillups. Beyond that, we'll probably start hitting the 90s here in TX so that temp would make further comparisons/reports meaningless...
*And to be fair, I calculate mpgs by looking at my mileage since the last fillup and using the nozzle auto-shutoff as my full tank indicator, and the gallons from that fillup to calculate... No, it's not perfect, but it works for me.
Couldn't figure out the squeak (apparently beyond the old mechanic's hearing range) but we worked up a sizeable bill on it... I hosed down my rear leafs with WD40 and the shackles w/ silicone spray and haven't heard it come back...
Regardless, mileage: In the month or so I had that standard gear oil in (I'm sure it was OE spec, which would be 75w90 I think -- these guys are by the book which I appreciate and late 50s/early 60s, two old toyota techs still working for themselves).
Last two fillups have been more highway than city and pretty close driving conditions, but I do a lot of mixed city/highway driving and work from home so don't have a standard commute, just a standard routine...
Tank with the dino rear diff gear oil was 12.36 mpg.
Latest tank with the amsoil 75w90 severe gear oil was 13.44 mpg.
I've been averaging right around 12.3 mpgs w/ the dino oil -- best tank in over a month of driving was 13.38 and worst was 11.10. With amsoil in the rear diff in the past I've hit 17.5 mpgs w/ purely highway driving, mid 14s with mixed city/highway but highway heavy, and generally see high 11 to low 12 mpg as my low end standard.
So I'd say, it's a pretty solid 1/2 to 1 1/2 mpg gain w/ that fluid for me and my truck. With a 1 mpg gain being the likeliest assumption at this point. Will post more numbers at the next two fillups. Beyond that, we'll probably start hitting the 90s here in TX so that temp would make further comparisons/reports meaningless...
*And to be fair, I calculate mpgs by looking at my mileage since the last fillup and using the nozzle auto-shutoff as my full tank indicator, and the gallons from that fillup to calculate... No, it's not perfect, but it works for me.
Last edited by RSR; 05-11-2015 at 02:10 AM.
05-11-2015, 02:10 AM
#6
Registered User
Thread Starter
One last thing. Just for the throttle response increase, this fluid switch was worth it for me... I feel substantially less driveline drag w/ the new fluid.
05-24-2015, 06:29 PM
#7
Registered User
Thread Starter
Latest tank was 12.56 mpg with mostly city and stop and go driving. Probably similar to a fillup on 4/18 where the preceding tank average 11.34 mpg. With increased outside temps, I'd estimate that tank would have probably been ~11.5 mpg. So likely a solid mpg gain again here.
Also, the last two fillups on dino diff oil prior to changing out to Amsoil, I was at 12.15 and 12.36 mpgs respectively with those miles being highly biased in favor of highway. So even then, I'm still coming in above those tanks...
MPG gains are real. Assuming an 11 mpg start, a 1 mpg gain to 12 mpg, is a 9% increase in mpgs -- so you get 9% more miles for the same amount of fuel as you would currently use. At 5k miles per year, that's an extra 450 miles.
Also, the last two fillups on dino diff oil prior to changing out to Amsoil, I was at 12.15 and 12.36 mpgs respectively with those miles being highly biased in favor of highway. So even then, I'm still coming in above those tanks...
MPG gains are real. Assuming an 11 mpg start, a 1 mpg gain to 12 mpg, is a 9% increase in mpgs -- so you get 9% more miles for the same amount of fuel as you would currently use. At 5k miles per year, that's an extra 450 miles.
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05-25-2015, 09:02 AM
#9
I'm not discrediting your experience in any way. I think it's a decent product but I don't see it as the perfect product they try to portray.
I'm always suspect of a study published or sponsored by a company trying to sell you their product. Same goes for any comparison in Consumer Reports or any automotive magazine. CircleTrack magazine was about the last one I trusted. These days the sponsorship and advertising dollars makes or breaks a publishing company.
It seems to me that alot of their salesman are old used car salesman or reborn snake oil salesman from the 1800's. Those guys make a bad impression and don't do the brand any favors.
I'm always suspect of a study published or sponsored by a company trying to sell you their product. Same goes for any comparison in Consumer Reports or any automotive magazine. CircleTrack magazine was about the last one I trusted. These days the sponsorship and advertising dollars makes or breaks a publishing company.
It seems to me that alot of their salesman are old used car salesman or reborn snake oil salesman from the 1800's. Those guys make a bad impression and don't do the brand any favors.
Last edited by Odin; 05-25-2015 at 09:32 AM.
06-21-2015, 10:50 PM
#10
Registered User
Thread Starter
Last 4 tanks were as follows, all mixed city/highway -- first much more city:
11.89 mpg
13.36 mpg
12.47 mpg
13.80 mpg
3/31 I had an 11.1 mpg tank and 4/18 I had an 11.34 mpg tank, so it's still higher than those low ones, which were the lowest tanks in the month or so preceding the fluid change...
Total mpg since early May fluid change is as follows (6 fillups -- usually fillup around 1/4 tank and have the 17 gal tank):
1053.28 miles, 81.37 gallons, 12.94 mpgs
6 fillups prior to the rear diff fluid change (late March to beginning of May):
892.75 miles, 73.45 gallons, 12.15 mpgs
Between the two averages, that's a 6.5% gain in mpgs and 0.79 gain in mpg. On the 81.37 gallons, that's like getting an extra 5 gallons for free (actually, 4.97 gallons). So 5 gallons * $2.50, means I saved $12.50 in the same time period, which covers more than 1/2 of the rear diff fluid replacement cost... After this next month, that rear diff fluid change alone will be putting $ back into my pocket.
Again, my city/highway driving can vary quite a bit, but never spend much time in this truck on the interstate (highways I drive usually have stop and go traffic and/or traffic lights so not constant speed). Constant speed highways, I've pushed 17mpg in this truck... But I didn't do any of those trips for either driving comparison period.
But my conclusion here is I do get a solid mpg gain of 1/2 to 1 mpg and the drivetrain drug went down here substantially.
I'm going to be doing other mods, so won't be posting back here w/ more updates. Consider this my final report.
11.89 mpg
13.36 mpg
12.47 mpg
13.80 mpg
3/31 I had an 11.1 mpg tank and 4/18 I had an 11.34 mpg tank, so it's still higher than those low ones, which were the lowest tanks in the month or so preceding the fluid change...
Total mpg since early May fluid change is as follows (6 fillups -- usually fillup around 1/4 tank and have the 17 gal tank):
1053.28 miles, 81.37 gallons, 12.94 mpgs
6 fillups prior to the rear diff fluid change (late March to beginning of May):
892.75 miles, 73.45 gallons, 12.15 mpgs
Between the two averages, that's a 6.5% gain in mpgs and 0.79 gain in mpg. On the 81.37 gallons, that's like getting an extra 5 gallons for free (actually, 4.97 gallons). So 5 gallons * $2.50, means I saved $12.50 in the same time period, which covers more than 1/2 of the rear diff fluid replacement cost... After this next month, that rear diff fluid change alone will be putting $ back into my pocket.
Again, my city/highway driving can vary quite a bit, but never spend much time in this truck on the interstate (highways I drive usually have stop and go traffic and/or traffic lights so not constant speed). Constant speed highways, I've pushed 17mpg in this truck... But I didn't do any of those trips for either driving comparison period.
But my conclusion here is I do get a solid mpg gain of 1/2 to 1 mpg and the drivetrain drug went down here substantially.
I'm going to be doing other mods, so won't be posting back here w/ more updates. Consider this my final report.
Last edited by RSR; 06-21-2015 at 11:09 PM.
06-21-2015, 11:00 PM
#11
Registered User
Thread Starter
I'm not discrediting your experience in any way. I think it's a decent product but I don't see it as the perfect product they try to portray.
I'm always suspect of a study published or sponsored by a company trying to sell you their product. Same goes for any comparison in Consumer Reports or any automotive magazine. CircleTrack magazine was about the last one I trusted. These days the sponsorship and advertising dollars makes or breaks a publishing company.
It seems to me that alot of their salesman are old used car salesman or reborn snake oil salesman from the 1800's. Those guys make a bad impression and don't do the brand any favors.
I'm always suspect of a study published or sponsored by a company trying to sell you their product. Same goes for any comparison in Consumer Reports or any automotive magazine. CircleTrack magazine was about the last one I trusted. These days the sponsorship and advertising dollars makes or breaks a publishing company.
It seems to me that alot of their salesman are old used car salesman or reborn snake oil salesman from the 1800's. Those guys make a bad impression and don't do the brand any favors.
Do I think Amsoil picks and chooses which tests they want to publicize? Yes. Do I think they're somehow trying to hoodwink consumers? No, I don't.
Amsoil's business model is basically independent dealers sell (Amsoil has rejected several attempts from national merchants to stock their products in store -- with the finicky American consumer this alone loses them business when product isn't available "on demand") and then Amsoil counts on the quality of their product to garner repeat business.
They put a lot of time and advertising into their remote bypass filter systems, and high mileage oil change capabilities -- products that frankly lead to them selling less overall product than they would otherwise and is exactly opposite of what high price business consultants with Harvard MBAs would tell them to do to maximize profits.
And then their prices are higher than big name oil products usually as well, so that too loses them business since they choose not to compete solely or primarily on price but rather on quality...
Me, I always choose quality first. I'm a perfectionist. I'm weird -- there aren't many like me... Amsoil seems to sell to folks like me, which means to me -- they found their niche in promoting highest quality and stay there...
YMMV of course, but I really don't think Amsoil or synthetic fluids generally are anything remotely like "snake oil."
06-21-2015, 11:04 PM
#12
Registered User
Thread Starter
I'm doing a drain and fill here soon w/ Mobil 1 synthetic which is supposed to be kosher w/ non-syn fluids. Will probably do a 2nd of those too in another 6 months or so. Should put me at 2/3rds or more new fluid. I'm installing a magnefine at the same time. I want to install a new tranny plate oil cooler (have the OE plate and fin from the towing package), aluminum radiator, and a couple other items when I do the full flush/fill w/ Amsoil...
Mainly, I worry about varnish, etc, coming loose on tranny when switching out to synthetic so figure I'd do a more gradual option instead of a shock switch... Can't afford a new tranny right now, haha.
Looking to get the LCE cat back exhaust w/ their annual 4th of july sale to get 10% off there too... Since planning more updates soon, that's why the final #s conclusion post.
Mainly, I worry about varnish, etc, coming loose on tranny when switching out to synthetic so figure I'd do a more gradual option instead of a shock switch... Can't afford a new tranny right now, haha.
Looking to get the LCE cat back exhaust w/ their annual 4th of july sale to get 10% off there too... Since planning more updates soon, that's why the final #s conclusion post.
06-22-2015, 06:33 AM
#13
Registered User
When I bought the 88 4runner for my wife it was averaging 15mpg. I changed both diffs to Mobile synthetic and the transmission to B&M trick shift and now it is getting 18 consistently.
06-22-2015, 09:15 AM
#14
The NAPA stores around me carry Amsoil, but they are the only ones. I run Amsoil in my motorcycle and Redline in my trucks transmission and rear end so I obviously don't hate their products and don't think synthetic fluids are snake oil.
I only used snake oil salesman to describe some of their salesman. I've seen a few on websites that just won't back off and that makes a bad impression and some stay clear of their products because of it.
Last edited by Odin; 06-22-2015 at 09:17 AM.
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