ATF for 2005 Buick 3.8L

[pbm]

My friend has a LaSabre that he purchased new in 2005 with approx. 43K.
I told him it was time to change the ATF (along with the PSF and coolant).
I told him I would do it for him because he has done several favors for me (plows my driveway every snowfall to name just one).
2005 was the last year of Dex III in GMs and Dex VI is supposed to be a replacement. I have read that not all GMs have liked Dex VI.
I have considered using Pennzoil Dex III, Pennzoil MV, Castrol Dex VI (currently on sale at AA) and Shell Dex III which was on closeout at BJs.
What are your thoughts on these ATFs in this application?

I guess I'm trying to decide whether to stick with what came in the car (Dex III) or 'upgrading' to Dex VI.

PS: I'm going to use Prestone AMM since it's a Dexclone and readily available.

 

[cchase]

Originally Posted By: pbm
PS: I'm going to use Prestone AMM since it's a Dexclone and readily available.


If you're going that route, why wouldn't you just get the Prestone Dexcool product? I was steered away from the "all makes, all models" several times.

 

[pbm]

Originally Posted By: cchase
Originally Posted By: pbm
PS: I'm going to use Prestone AMM since it's a Dexclone and readily available.


If you're going that route, why wouldn't you just get the Prestone Dexcool product? I was steered away from the "all makes, all models" several times.



I know what you mean. A few years ago I read that AMM and Prestone Dexcool are exactly the same product minus the dye. For a few bucks it might be worth it to use orange coolant.

 

[ls1mike]

I put Dex VI in my 98 Regal. Your buddies ride has the same transmission with a bunch of updates. It will like DEX VI.

 

[Boss302fan]

In your application, many here use and recommend Maxlife ATF.

Using the Prestone 5/150 is fine as long as you do a complete flush to get out all the Dexcool. I did this in my sons 03 Monte Carlo SS and it has been running great.

 

[sciphi]

Either Dex-VI or Maxlife would be a good ATF choice, IMO. If you want to go higher-end, Amsoil ATF or ATL is supposed to work very nicely.

Coolant: Use the Prestone after a full flush of the Dex-Cool.

PSF: Maxlife, or another synthetic fluid of your choice. ATF seems to work much better than PSF in my Buick's power steering system, with easier effort and less noise.

 

[unDummy]

Coolant, ANY Dexcool or Dexclone.

ATF: ANY DexronVI or full synthetic DexronIII. If on a budget, Maxlife, Amalie, Castrol HM, or ANY Mercon-V will work well.

PSF: Amsoil, Lubegard, or GM Cold Climate

 

[Whitewolf]

There is no DEXRON-III and has not been for some years now. Many companies are marketing fluids as being DEXRON-III but they have no evidence to support those claims.

Use DEXRON-VI it is valid and OEM supported.

 

[mechanicx]

I would be more concerned about the Prestone Dexcool since I think this application has plain reservoir. Havoline or Zerex Dexcool might be hard to find but I believe it is more resistant to gumming. Any Dexcool will probably be OK though. The main thing is if you use Dexcool and Dex VI you are following manufacturer recommendations and you can find the manufacturer's documents and dealer to back that up.

 

[pbm]

Originally Posted By: Whitewolf
There is no DEXRON-III and has not been for some years now. Many companies are marketing fluids as being DEXRON-III but they have no evidence to support those claims.

Use DEXRON-VI it is valid and OEM supported.



I feel the major companies like SOPUS that are selling ATFs that say "for use in vehicles that formerly required Dex 3..." are selling products that met the spec when it existed. In other words I don't see them changing formulas (to save a few bucks) from what they previously marketed.
I think the oil companies know more about lubricants than the car companies.

 

[Shovel Head Ted]

I have a park ave with the 3.8. I use Amsoil atf in it.Works great.It is dexIII. I have not tried the new atl witch is dexVI. Maybe next time.