Mongo

I just got my car back from the shop this morning for a 30,000 transmission service (fluid, filter, gasket, etc) and this car shifts so smooth it's scary.

I used Valvoline Dextron VI ATF in the car and am quite impressed with the results. Absolutely amazing! The transmission slip (or flare) from 2nd to 3rd is gone! The car now immediately starts in first gear when applying 1/3 throttle. Best of all - the reservoir is no longer overfilled and overflowing!

Dextron-VI ATF? Greatest thing next to sliced bread for the 928!

Mongo

Damn this stuff is hard to find! I bought it at Kragen, but have gone to Autozone, Walmart, Target and Napa - neither of these stores have it! The next best place to Kragen to get it is Pep Boys.

At least it's a buck cheaper than Mobil 1 ATF.

Jack Riffle

I was curious about those fluids rated higher than Dexron3. Let us know how it does after 6 months or so....

Mongo

I'm curious to know too. However, if a fluid that's rated higher than Dextron-III can be used in cars where Dex-III is recommended, I don't think there should be any problems. Nothing hasn't happened weird so far....except maybe smoother shifting.

SeanR

I was hoping there would be more comments on this thread. I'm going to do mine this weekend and am interested on other opinions.

Should I do it or should I not.....I've got a few days to think about it.

dr bob

Look at the bottle and verify that the "new" Dexron is fully compatible/plug-in replacement for the Dexron-III and -IV and -V/mercon that we already know is OK.

Remember that the ATF friction and viscosity index numbers are constant from version to version. Have to be to maintain backwards compatibility. The heat resistance and viscosity breakdown are the things that tend to be improved from version to version. When someone suggests that the car shifts a lot better with particular fluid, it's quite likely that one would see a similar improvement with almost any compatible replacement fluid. Consider that the ATF gets swapped on maintenance schedule at 25-50k miles, or every five years for me worst case. If a premium high-temp syn ATF is a couple dollars more per bottle, it works out to pennies per day or less. Go with whatever spins your prop. My only warning might be to stay clear of the Royal Purple stuff, which seems to be hype ahead of function for many of their products. A high price alone does not make it a premium product.


I like the Mobil-1 full-synth ATF, especially for towing. Nice firm shifts in the 928 box too. Wal-Mart sells it.

SeanR

I was looking at that bottle the other day and figured I'd wait until the last minute to purchase the stuff.

BTW, thanks for returning my call this past weekend. We "trusted our measurements" and it worked out well.

Mongo

It took me 2 weeks to decide what ATF to put in this car. I checked the Valvoline website to make sure that the Dex-VI was backwards compatible, asked my old Porsche mechanic and various others that are knowledgeable with transmissions. If Dex-III is required/recommended for the 928, Dextron VI will NOT hurt it.

Mongo

After 1 year, here's an update.

Not much to say but Dexron VI is still keeping the transmission shifting smoothly.

86'928S MeteorGrey

Thanks for the update. I looked long and hard at the Dextron VI, including this thread. I ended up going with Mobil 1 syn for engine, gearbox, and tranny. I might have been swayed if you posted 4 days earlier... On second thought, maybe Dextron VI makes smog police and cops come after you?