Life of ATF fluid?

[Bill in Utah]

I'm thinking of buying a case of Amsoil ATF fluid for drain and refills on my 2007 Subaru Outback since Amsoil just added a approved fluid on their list a month ago...

Question is if I buy a case, how many drain / fills would I be able to get and how long is ATF good for in a garage that sees low 30s to high 80s year around?

I've had a stash of motor oil and used 7-9 year old oil with no problems, but I'm new to the ATF world..

My plan is to do drain and fills every year and replace the spin on filter at that time. Mileage would be around 12-15k I think...

Thanks in advance! bill

 

[Lonnie]

In fleet work the tech staff of most major supplies all say 5 years max, avoid below freezing and over 100F. How about storing it under the bed?

 

[Pablo]

The diurnal temp swings bug me. 5 years in ideal conditions. ATF being a lightly additized fluid is less likely to suffer from drop out, but condensation always seems possible, even in a "sealed" bottle.

Another thing - I would actually think twice about yearly drain and fills - 2x per year may be more prudent. See the ATF change over calculator - you'll start to see diminishing returns, but also you'll see how much fluid is left behind. Plug the numbers in different ways to get a feel. I'm not saying a blend will harm anything, just don't like aging original fluid left behind.

 

[Donald]

Pablo - the Amsoil ATF is listed for 50K miles for severe and 100K for normal service. He is saying he will go 15K-18K miles/year. He is looking at a drain and refill every year so he will introduce maybe 40%-50% new fluid yearly.

One minor problem with keeping oil or ATF for years is that the company will probably improve the oil over that time period.

 

[Pablo]

Well the 50K-100K is based on 100% Amsoil ATF. You will need to back off on that for any amount of blending. That AT holds - 10 quarts?? Draining yields - how much???

 

[unDummy]

If the manufacturer claims that the factory fill is good for xxk miles, then the yearly drain/refill is a good maintenance program.
Sure, BiTOG members like me, would like to see you drain/refill at every oil change or 7.5k. But, that can become a hassle and be costly. If the vehicle isn't driven aggressively, it isn't really needed.

There are cars out there with NO ATF maintenance that are over 10 years old, driven all 4 seasons, and still run fine. So, I would NOT worry about 5+ years of sealed bottle ATF storage if your goal is to grab several ca$es now.

The yearly ATF filter change is a good idea. But, it can go 2 years or 30k, especially if you grab a boutique filter or oversized option.

My only other recommendation is the 'OR' word. Drain/refill 15k OR yearly, whichever comes first.

 

[Dick in Falls Church]

Well, the transmission holds about 10 qts total.
Have no idea how much you can drain/suction out.

The ATF in the bottle is subject to less potential for dilution/contamination that the ATF in the car.

You might want to drain and refill, drive a bit to mix, and repeat it. I don't see any problem with leaving the OEM fluid in the blend, since the car is basically new.

When I've picked up used cars, most of them have held approximately 1/3 the total in the pan. I've changed the fluid in the pan three times with fresh non-synthetic, then again 3 times with the synthetic. At least I've got fresh stuff in.


Then, in I remember and still have the car, I'll drain and refill the pan again at 50K

 

[mikeg5]

put the bottles of atf under you sink or somewhere in the house where temps are more consistant.. if you are going to pay that much for atf your best bet is to have someone flush the old out and put in all new amsoil fluid..to me the drain and fills wouldnt be ideal in this situation.. now if you were using something cheaper like most over the counter atf's then drain and fills would be ok... imo

 

[Donald]

I'd go for the poor man's flush that has been mentioned several times in this forum.

 

[Tempest]

I think temp fluctuations are over blown. The fluid goes from ambient to 150F+ every time you run the car, and the fluid lasts for years (especially a fluid this robust).