mobil 1 vs redline diff fluid

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It depends on what are the applications, for differential application I prefer M1 due to long distance durability. I find Redline changes a bit if the diff is not fully sealed (has breather with moist atmosphere). However, for new diff that has no noise issue or application to have less drag, I believe Redline has advantage. However, Redline has more options that may have better suitability for worn diff scenario, as well as for transaxle/gearbox application.
 
I never noticed a difference. I've been running both at various times in my truck. I doubt a simple, open diff cares that much under normal operating conditions.
 
Used to run Mobil-1 in my Toyota Corolla - manual trans and diff. Very smooth transmission. Who knows about the diff? No problems with it, though. I kept the car for 24 years.

I now have Redline GL4 in my Tacoma's manual trans, and Amsoil in the diffs. I would have used Redline in the diffs (4wd), but it was on back order when I was ready to do it.

You'll be fine with either, IMO.

I also saw a slight MPG improvement when I changed the factory fill to synthetic.
 
Lots of folks swoon over redline, but IME with a noisy diff, it didn't do the job. Unfortunately what did was specialty formulations,,which you cannot get...

I've seen firsthand how M1 cleans dirty build-up in differentials. I've also been pleased with Amsoil SVG.

Though this isn't about MTF, I've never found theirs to hold up.

I have no indication that redline is anything special, do they even say that it is POE in many real quantity?
 
Originally Posted By: 147_Grain
Amsoil Severe Gear Oil or Redline are both superior to Mobil.


How so? I'm trying to understand, as later this year I will be changing the fluid in the transfer cases on my Outback.
 
Originally Posted By: Clevy
Originally Posted By: GutsyGecko
Redline all the way!



Yep. It's the best money can buy.


How so? Please help me understand.
 
Originally Posted By: BHopkins
Originally Posted By: Clevy
Originally Posted By: GutsyGecko
Redline all the way!



Yep. It's the best money can buy.


How so? Please help me understand.


You have to raise an eyebrow when some claim the best is this or the best is that. However I haven't used RL or Ams gear lube, but from my experience, M1 75-90 has been outstanding in the rear wheel drive vehicles I have owned.
 
I had to buy a special Torx bit and needed a special funnel to change the diff fluids in my 2009 Forester. So, while on Amazon, I ordered 6 quart of RL's 75w90 fluid.

I was going to use M1, but for a few bucks more, I decided to go with the RL product.

Mostly because I wanted to try it. Never used RL in anything, except their 2-stroke oil in my scooters. So, I had an itch that needed scratched.

I don't own anything exotic enough or high performance enough to buy RL engine oil. At least not yet.
 
Originally Posted By: tig1
Originally Posted By: BHopkins
Originally Posted By: Clevy
Originally Posted By: GutsyGecko
Redline all the way!



Yep. It's the best money can buy.


How so? Please help me understand.


You have to raise an eyebrow when some claim the best is this or the best is that. However I haven't used RL or Ams gear lube, but from my experience, M1 75-90 has been outstanding in the rear wheel drive vehicles I have owned.


That is why I asked. But if someone has some evidence to support these claims, I'd sure be interested.

Personally, I suspect that all three are fine products that would provide superior lubrication in most any daily application. (We are talking about a Subaru Forester here. Not a race car. Or a Cat D8.

Clearly, Mobil has an advantage in the research and development of being part of fortune 500 (they were #2 in 2012. Not sure for 2013.) company. That is something that neither Red Line or Amsoil has. In regards to R&D prowess, I have always wondered how Amsoil competes against the big boys. And in the current market of advanced lubrications, I think it would be foolish to ignore that.
 
My rear diff has M1 75w-140 (I think) and the fluid is still clean after 45,000. The only thing I have to compare it to was the old fluid which was diesel soot dark.

I'm changing it with Valvoline dino tomorrow. If you change them at roughly 30,000 miles, unlike me, old fashioned dino is more than sufficient for normal use. $5 something a quart cant be beat. ST gear oil is $4 something a quart. I only bought Valvoline because I was in Meijer and it was easier to get at the moment.
 
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I think you have answered your own question. All you're likely to get is anecdotal evidence and opinion. Mobil 1 75-90 is a fine product . It's in my Silverado - use it sleep well!
 
Heh heh. The 4 speed auto in my 528es proved to be more trouble free and quieter than the 5 spd manuals. The lay shaft bearings wear and the shaft rattles. The cure is to turn up the volume on the radio. A thicker lube affects shifting. Dont worry, the 5spd is a very tough unit. I know of a car where it was drained and never refilled. Then driven from Richmond to Jacksonville. It was squeaking ! A refill , resulted in a functioning transmission that jingled at an idle.
laugh.gif
 
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