Mobil1 vs Amsoil Synthetic ATF

[J_D]

Gentlemen,

I recently came across this website, and registered today. I desperately need some scientifically based objective advice selecting an automatic transmission fluid. I did not find anything in a search to answer my general questions, and apologize if I overlooked any related threads.

I have a Ford F250 with an E40D automatic transmission. It has 100,000 miles on the odometer. The transmission capacity is 18 quarts in a full ATF fluid change. I use this truck predominantly for heavy hauling or towing, mostly in mountainous high altitudes. The E40D transmission apparently has a reputation for failing, especially the older models such as this one. If I can keep it on the road longer than is typical using a better fluid, that would be a big victory. Good replacement transmissions cost around $5000.

Ford originally called for Mercon to be used in this transmission. Ford stopped licensing Mercon specification, replacing it with the Mercon V specification, for use in all previous Mercon specified applications several years ago. Mercon V is about $6 per quart.

I would like to use something even better than the Ford Mercon V specification if it is likely to help and if it's not too costly. Amsoil "Synthetic Multi-Vehicle Automatic Transmission Fluid" and Mobil 1 Synthetic ATF both claim to be as good or better than Mercon V. Both are around $9 per quart. So my cost will be about $54 more for 18 quarts of either of these synthetics, compared to Mercon V. That seems justified if they are truly better ATF fluids.

My local Ford dealer and parts suppliers don't seem knowledgeable or convincing about any of this - they seem to have mostly hearsay and opinions. Can somebody with technical knowledge of either of these particular "synthetic" ATF fluids please weigh in on this decision?

Thanks,

Jan

 

[Warstud]

Repost!

 

[buster]

I don't know much about ATF's, but both are good. I hear a lot of good things about Amsoil's ATF. Don't know much about Mobil ATF's. Maybe someone else will chime in.

 

[Donald]

Two things will help. A synthetic ATF which can stand up to the heat and a lot of other things better than regular ATF.

Also an inline filter (spin-on if you have room) or a Magnefine will help also.

Then there is the question of how you will do a total fluid exchange to get the new ATF in there.

Change the normal filter in the transmission also.

 

[bmwtechguy]

I can tell you I have a RWD 4 speed transmission in a 91 Caprice that has been used a lot for towing over the years. Currently has 318k miles on the original transmission and over 180k miles on the Amsoil ATF. Along with the better ATF, I installed a large aux cooler and inline Magnefine filter at 133k miles when I got the car. The fluid still looks bright red on the dipstick, and when I have had an unsuspecting fellow techs look at the fluid on the dipstick, they always say it looks like it was just changed...don't change it yet! Transmission still shifts very well and is quiet. Technical info still needed?

If I had to guess, I would say that Amsoil is a better quality fluid than Mobil 1. How much better is anybody's guess. I can get Amsoil for $9 a qt and M1 for $6/qt.

 

[oilboy123]

Been using the Amsoil ATF for 15 years. I put a Transmission exchange rebuilt trans in my dad's older 91 Caravan. I was going to run it in on some dino fluid for a few K miles then switch it over to Amsoil. But I just put in the trans and installed Amsoil. I then put a Magnifine filter on it about 10k later. I ran the trans to 80K with the trans breaking in on the Amsoil fluid.

The fluid still looked good when I changed it. In fact it was still bright cherry red and the pan and filters were spotless. I thought I would see some debris from break in. Granted this is a front drive minivan that did no towing, but I was still impressed. I figure the price difference is well worth it for the extra margin of protection Amsoil provides. But some people like using a fluid that is less expensive, and to change it more often. I'm not one of them.

 

[Pablo]

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2356700

 

[Donald]

If I had my choice I would (and do) use Amsoil. In ATs and transfer cases where specified.

 

[J_D]

Everyone,

Thanks for all the advice! I will replace my current ATF cooler with a larger model. Amsoil is not as readily available as M1. Unfortunately there are no Advance Auto Parts stores out here around the Lake Tahoe/Carson Valley area either. Looks like they have great deals on M1 products. I have not found it any less than $9.09 per qt in my region. About $176 with tax for this ATF fluid change. I've drained the TC which in combination with the pan makes up at least a 95% fluid change. No flushing at this price for fluid! Read lots of warnings about the various flushing procedures too.

Thanks Again,

Jan

 

[J_D]

I assume a wear test analysis is relevant to ATF fluids. I was hoping somebody had test results for identical wear tests on the Amsoil and M1 product. Can anybody tell me what it costs to have oil testing/analysis done? Does it include wear testing?

Thanks,

Jan

 

[bmwtechguy]

The lubricant blenders, formulators and additive manufacturers use standardized wear tests and many other tests on fully formulated lubricants and fluids. This testing is expensive as the equipment is sort of exclusive to labs, etc. As consumers we pretty much only have access to whatever test results these companies decide to share with us, such as physical properties of a fluid, etc. So we are left with sending samples of used fluids to labs such as Blackstone and trying to decipher the results of such used oil/fluid analysis to compare how much wear is taking place. Drawing definite conclusions to compare 2 fluids is not that easy, and this testing can get expensive too.

Both fluids are very good, but priced comparably, I would choose Amsoil, hands down, based on my own experience and others I have read. I have used both.

 

[tig1]

Originally Posted By: J_D
I assume a wear test analysis is relevant to ATF fluids. I was hoping somebody had test results for identical wear tests on the Amsoil and M1 product. Can anybody tell me what it costs to have oil testing/analysis done? Does it include wear testing?

Thanks,

Jan


Wear test? My wear test is if the tranny is still goin after 250K, it passed.