Mixing ATF's

[hominid7]

I'm certain this has been covered but for the life of me i cant seem to find reliable information...

Can Dexron/Mercon III and Mercon V be mixed in a transmission that is spec'd for Mercon and has been now approved for Mercon V?

Car has 100% DexronIII/Mercon in it now and thinking of doing a drain and fill at some point in the future using Mercon V or a multi-use ATF that is MerconV rated.

 

[unDummy]

Yep!
Now that you have clean ATF from a flush, regular drain/refills will keep it clean.

 

[hominid7]

That's my plan, a drain and fill every 10,000 miles or so, but at that rate just using walmart or coastal dexIII/merc may be good enough..?!?

 

[unDummy]

10k or at least once a year is reasaonable. Any ATF is OK.

But why cut corners? Its not like Mazda has a great reputation with their self destructing automatics.

Consider quality name brand fluids. If over 100k miles, use one of the high mileage ATFs.

If it were mine I would ugrade to a synthetic blend. Any of the Mercon-V's or multivehicle ATFs would work great for those 10k intervals.

If store brand is your choice, Walmart and coastal have high mileage and multivehicle ATFs.

 

[Cutehumor]

I just mixed 2 qts castrol dex 3 multi vehicle atf with 1.5 qt mobil 1 dex 3 atf and a full bottle of lubegard red for my 96 sunfire. I used castrol dex 3 multi vehicle because they don't seem to sell only dex 3 anymore. what do I know, my 96 sunfire 3 speed auto hasn't been serviced in 50k miles/5 years. no drain plug, have to drop the pan/filter to change fluid. The manual says change 50k severe use. I use it for normal driving, it doesn't have to be changed. I just go by the severe rec's for the auto transmission

 

[Doc8404]

I'll be doing drain and fills with Amsoil ATF on the Honda and F150 from now on.

Honda's transmission rebuilt at 109k and will drain/fill at 114k and 120k.

 

[hominid7]

Quote:

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But why cut corners? Its not like Mazda has a great reputation with their self destructing automatics.

Consider quality name brand fluids.

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Unfortunatly you are so right.

It now has Shell DexIII/Mercon. According to the Shell spec sheets, the Shell, Pennzoil, and Quakerstate ATF's all look identical in the DexIII/Mercon formulation.

I'll likely stick with Pennzoil Dex/Mercon or upgrade to Pennzoil Multi ATF blend that is Mercon V rated.

For some unknown reason i'm on a SOPUS kick lately that's been hard to shake

My only recommendation to Pennzoil would be to make your regular ATF bottles a color other than yellow. I came close to putting 5w30 in my power steering the other day!