What's the scoop on Dex VI? Should I change?

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Both vehicles are in sig. Malibu has old school 4T45E 4 speed and the truck has the new 6L80E six speed. Both the Malibu and Silverado are daily drivers, but the truck sees LOTS of in town short mileage trips topped off with some light/moderate long distance towing of 19 foot ski boat plus the fam. Is Dexron VI a good enough successor to the previous Dexrons for my apps, or should I invest in a full syn ATF like Amsoil? I NEVER go over 50K between fluid flush/filter change (more like 40Kish). Thanks.
 
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Dex 6 is good and is probably good enuf for the Malibu. for the Silvo I would pop for a full synthetic (heavy truck, towing) although I dont know the price difference.
 
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For some reason I thought dex 6 was some super lightweight trans fluid? high efficiency stuff?? I don't know if it would be the best to upgrade your older stuff? I know a lot of times they say they are backward compatible.
 

zulu

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 Originally Posted By: Jdblya
For some reason I thought dex 6 was some super lightweight trans fluid? high efficiency stuff?? I don't know if it would be the best to upgrade your older stuff? I know a lot of times they say they are backward compatible.
Both vehicles are FF with Dex IV. I was just wondering if I should change or if it will suffice?
 
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I have a mix of Dex VI and Castrol High Mileage in my car right now. The Dex VI gives quick firm shifts. Not as firm as Mobil 1 though. At least there last formulation. I think when it came out GM said it was good for 100 to 150 thousand miles. And yeah its thin stuff. Like around 6 cst compared to 7 and higher for most dex 3 fluids. I would go with the Dex VI I think its a major improvement over Dex 3 and GM has tight control over how its formulated. http://www.castrol.com/castrol/sectiongenericarticle.do?categoryId=9012227&contentId=7028225
 
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The main advantage of the Dex VI is longer drain intervals, and slight improvment in fuel economy because it's thin. It's already a group III base stock IIRC. There is no such thing as DEX IV,
 

dnewton3

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The viscosity retention and oxidation resistance of DEX VI are about 2x those of the fluid it replaced (DEX IIIh); that's a major improvement. While the viscosity does start lower than that of a (former) DEX III product, it actually retains the viscosity better, and after some accumulation of mileage, will be more viscus than the DEX III after it breaks down. While it might be quesitonable for some, I see no reason whatsoever to not use this stuff to it's full capability. Dumping it early is akin to dumping engine oil too early; it's a waste. Especiallly in the 6L80E, which was specifically designed with the DEX VI fluid in mind when it was developed. Is DEX VI as good as top end PAO products? No - not likely. But it is world's ahead of the stuff it replaced, in some situations. It is NOT reasonably suggested to be used in older Allison 1000 series trannies in the HD trucks, to the contradiction of GMs "official" statement; chemistry creates problems for the pump seals. This information comes (quietly) from a source inside Allison. There are serial number cut-off points for where Allison suggests not using DEX VI before they made seal material changes to address the compatibility issue. It became a real he-said/she-said thing when GM owned Allison. Now, Allison is a bit more open about disagreeing with GM. However, for most of GMs products, DEX VI is a step forward. When it first came out, it was hard to find VI anywhere but at the GM stealership, and it was pricey! Now, you can find it everywhere for a reasonable price. Licensed stuff is even available in ST-brand at WallyWorld now. It's not the "perfect" fluid; nothing is. But it's a decent fluid that you shouldn't dump in 25k miles either; it will do a fine job in many situations and last much longer than the (former) DEX III. In your specific applicaitons, going around 40k miles on DEX VI is perfectly doable, and you'd still have life left in the fluid when you dump it. Short trips mean nothing to tranny fluids, overall. Even towing with the truck, you should easily get 50k miles from it. If you REALLY want to know how it's doing, get a UOA. I think you'd be suprised how well it performs.
 
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GM didn't specify what base oil to use in Dexron-VI; they just specified the performance requirements. To meet these requirements a Group II & Group III blend or better must be used. I'm with dnewton. For $22.50 at at Blackstone or a similar lab you can get the fluid tested and know what's happening. It will likely save you a lot of money. Dexron-VI and the other new generation OEM fluids are very long life fluids. Don't throw them away and spend money based on guesswork.
 

PT1

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 Originally Posted By: dnewton3
While it might be quesitonable for some, I see no reason whatsoever to not use this stuff to it's full capability. Dumping it early is akin to dumping engine oil too early; it's a waste.
I used to agree until I started changing my own ATF and saw what was coming out in my GM 4L60 transmissions at 30-50k. Not pretty. I just don't like all that garbage floating around in there for the price of a cooler line flush which for a DIY is usually about $100 using premium fluid. I change DexIII at 30k and DexVI at 50k.
 
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 Quote:
Here’s what GM has to say about the new DEXRON VI: Automatic transmission fluid (ATF) is considered the life-blood of the automatic transmission. It is used to transfer power in the torque converter and provide the pressure to apply the transmission’s various clutches and bands. It also is used to clean, lubricate and cool the components of the transmission. GM’s new transmission fluid, DEXRON®-VI, was developed to have a more consistent viscosity profile; a more consistent shift performance in extreme conditions; and less degradation over time. Beginning with the design and development of GM’s new Hydra-Matic 6-speed rear-wheel-drive transmissions, GM Powertrain engineers determined the need for a new transmission fluid to withstand the complexity of the clutch-to-clutch transmission operation. Additionally, GM engineers identified opportunities to improve viscosity, durability, and impact on fuel economy with a new fluid. "The development of DEXRON®-VI is the first time an automotive company has worked so closely with petroleum and additive companies to develop a new fluid," says Roy Fewkes, driveline fluids group leader, GM Powertrain. "The result is a new fluid that significantly outperforms existing fluids in every aspect. In fact, we have had to significantly extend the length of our durability tests to fully test the fluid’s capability." Internal GM tests have demonstrated DEXRON®-VI to deliver more than twice the durability and stability in friction tests compared to existing fluids. It also has demonstrated superior performance in pitting, foaming, oxidation and shear stability tests. Here’s what it means for ZZPerformance and your our transmissions: We believe in delivering the best possible transmission in the world. This means keeping up on all the latest technologies and constantly striving to improve all of our product offerings. The new Dexron 6 transmission fluid allows us to deliver a transmission that lasts longer, performs better and at the same time gets better gas mileage. The viscosity of Dexron 6 drops from 36 to 30 on cold starts and a little when warmed up as well. All while delivering better shifting and better protection during hot operation. Bottom line is longer clutch life, quicker shifts, improved fuel economy and more HP put to the ground.
 
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