Automatic Transmission Fluid (ATF) and the Gen 7 V6 5AT.

Almost all 5AT (Transmission) failures have occured with owners running Honda Z1 ATF fluid, but you are told by Honda and the Honda forum "experts" (
owned a vehicle more than one week and knows how to Google) that only Honda Z1 can be used, otherwise your transmission is doomed and will fail.

Hundreds of 5AT's fail and the forum "experts" proclaim that Honda transmission's have a fault and thats why it failed, no way could  Honda magic Z1 fluid cause or contribute to the failure.

One person has a failure with a higher mileage transmission after changing to Non Honda fluid and the forum "experts" proclaim, "we told you so", it's the fluid that caused the failure not Honda transmission flaws and you should have only used Honda magic Z1.

The utter nonsense spread on forums by posters new to Honda vehicles and transmission history and internal functioning seems to never end. Old wives tales and noob one line quotes have seen Hondas mystical "Dinosaur oil" (Z1 ATF) placed high on the altar of illogical snivelling worship.

Personally, the only time I would have run Z1 or Z1's replacement, DW-1, would be to comply with Honda's pathetic totalitarian mindset when enforcing transmission warranty acceptance.

Some of us have been running fully synthetic transmission fluid for years, well, it had to be non Honda if you wanted a TRUE fully synthetic QUALITY AT fluid - and it STILL has to be NON OEM as DW-1 is not a true fully sunthetic fluid - look at the base stock.

We ask - After years of running Redline D4 why aren't our transmissions destroyed? Oh, of course, we were just lucky, but our transmissions will die any second they say. It's a Honda G7 5AT and all G7 5AT's are basically the same, mine is from the "bad" years. This utter illogical blind stupidity to decry anyone using non Honda AT fluid is passed off as intelligent reasoning, and you get the same old tired noob response trotted out as fact every time you talk about ATF in a 5AT.
In the early days of the 5AT, a few owners tried non Honda fluid and had absolutely no problem running with the fluid, most had positive results. One or two owners complained of harsh shifting or strange behaviour and of course the non Honda fluid was to blame and proclaimed as BAD for any 5AT. Today we are seeing owners changing over to DW-1 "Honda Z1 replacement", guess what, a few are complaining of harsh shifting and strange behaviour running Honda DW-1. Now where are the doomsday peddlers proclaiming that DW-1 is not good for our transmissions - what a joke - not a peep because it's Honda magic fluid.

What most don't want to hear is the possibility of a problem with these transmissions that is being masked by the huge amount of FM and the higher Viscosity of Z1 (higher than DW-1). In each cases switching back to Z1 masks the problem. This is partly where some of these Old wives tales started and they got handed down as gospel.

More and more owners started decreasing transmission fluid change intervals - sometimes at every 2nd engine oil change - to help their transmissions survive when it became obvious that an inferior fluid like Z1 (look at the specs) was rapidity breaking down under most common driving conditions. Some of us started to look for a true fully synthetic fluid and found a few fluids that worked well.

Mobile one, Royal Purple, Redline and a few others worked well, but I found at the time that Redline D4 has Friction Modifiers (FM) and a Viscosity that is close to Z1, but in a far superior higher temp fluid that did not break down at the same rate as Z1.

When I changed over to Redline D4 I had brand new Z1 in my transmission. I had used Z1 to flush all the old fluid that had been in there for 60,000 miles (the mileage at the time I purchased the vehicle), Honda would have left that old fluid in there for at least another 30,000 miles and then ONLY REPLACED 3 litres - Un-freaking-believable! - as that fluid was nasty and way overdue for a FULL 3x3 replacement.

I also removed the old transmission filter - the one that Honda said didn't exist, and if it did, then it would never need replacing anyway!

The old filter was coated with black hard metallic paste and partly blocked (I tested it). I fitted an external transmission filter and also a larger ATF cooler for my hot climate - only years later did I realised just how important that filter change and ATF cooler were in keeping the TC (Torque Convertor) in the 5AT alive due to another Honda design flaw . See Cooler Circuit.

A short time later I replaced the 3rd and 4th gear Pressure switches - Major improvement in every aspect of the transmission - You must do this every 3 or 4 years if you want your transmission to survive. See Pressure Switches.
A few months later I went to a full replacement with Redline D4 synthetic fluid. That was years ago and the results were brilliant. Redline D4 felt so much better than new Z1. Slightly faster, tighter gear engagements and I could now feel the TC (Torque Convertor) lock/unlock. That Z1 slush feeling was reduced and cold morning AT performance was greatly improved. No harsh shifts at all, if anything, everything was even smoother.

In 2010, I read about tests being carried out by two pioneering owners over at AcuraZine forum. They had been running synthetic fluid for years and decided to try reducing the amount of FM in the fluid. A lot of thought and research was carried out by these two owners and has never really been appreciated, even to this day. See Lowering FM in ATF.

Of course the doomsday peddlers came out and preached transmission oblivion.

The findings and results described by these two and my own reading and research led me to try lowering FM, but I went a bit conservative and reduced my FM by a lesser amount, achieved by mixing Lightweight Racing (Type F non FM fluid) with the Redline D4, this also reduced the Viscosity to just below Honda DW-1.

The results were a bit like going from Z1 to D4 all over again. No harsh shifts, no harsh downshifting under grade logic, slightly faster gear engagements, really smooth and quick, always in the right gear and no hesitation. I would use caution though - some transmissions may have very close tolerances and lower FM can increase wear when two clutch packs fight against each other - Honda shift logic - especially in 2nd to 3rd shifts, It's important to watch for any increased buildup on the drain plug and any feeling of even slight deceleration during up shifts. Straight D4 is always the safer opiton.  

Almost three years later I preformed one 3 litre ATF fluid change, there was nothing on the magnetic drain plug except for a tiny amount of black material that typically covers the entire magnetic plug, not a single bit of metallic fuzz which is normally found. I strained the old fluid through a coffee strainer and it was spotless and still looked almost new. I have since gone back to straight D4 as I find it best for this hotter climate - and no hassles with mixing.

Would I suggest that anyone change to non Honda fluid - ABSOLUTLY NOT! -

Because of forum noob hysteria and the following.

1: Most transmissions are getting up in miles and years and likely had no transmission servicing at all - as per Hondas service interval.

2: If dealer serviced, they likely have had ONLY ONE 3 litre change. The dealer will change only one third of the old fluid and send you on
your way for another 60,000 miles. This transmission desperately needs a full 3 times 3 litre fluid change.

3: Most have never had the Pressure Switches replaced. - The dealer won't replace them unless they throw a code. So owners are
already suffering ever greater accelerated 3rd gear clutch pack wear. See Third Clutch Pack.

4: Most would be running the original partly blocked transmission filter.  - The dealer won't replace it. See Cooler Flow circuit.

5: Most owner are changing transmission fluid because they "finally" notice something strange or vague with transmission shifting.

6: I have no idea how bad the transmission is shifting - Most owners have no idea how the transmission should feel and over the years have forgotten how it felt when new. And most owners are unaware that there is even a problem with the shifting pattern.

7: Most vehicles are likely second hand purchases with an unknown driving history or unknown service history in some cases.

This means that if "Honda Magic fluid" is not used, ANY FAILURE will be blamed on the use of a non OEM fluid.

You have to decide for yourself - you need to read and educate yourself and make the best call you can based on knowledge, not nonsense. New vehicle owners, still wet behind the ears who think they know it all and do quick Google searches are posting the results as fact or giving uneducated personal opinions as fact based on common standard transmission myths, no understanding of how the Honda 5AT works or design flaws with this unit and hearsay and miss information from other noobs.

Be aware of the following if you decide to reduce FM in the ATF instead of just running straight Redline D4 ATF:

Some owners have completely misunderstood the mixing procedure for reducing FM and the correct amount of FM to maintain. This can create a problem with their transmission. They panic, revert back to Z1 or DW-1 and find it's ok again, of course they proclaim that reduced FM sucks and Redline fluid is no good for the 5AT - Another noob picks up on the post, doesn't understand the mistake made by the owner, why FM is used and how the 5AT clutch packs and gear changes operate with heavy FM fluid. He agrees with the owner and they both warn the world against using anything but Honda magic oil. Usually they post on other forums warning that non Honda fluids like Redline or reduced FM fluid has been proven to damage the Honda 5AT.

And again when reducing FM: Use caution - some transmissions may have very close tolerances and lower FM can increase wear when two clutch packs fight against each other, - Honda shift logic - especially in 2nd to 3rd shifts, It's important to watch for any increased buildup on the drain plug and any feeling of even slight deceleration during up shifts. Straight D4 is always the safer option.

Yet almost 100% of all 5AT failures were running Honda fluid. OH! that's right -

A : If it used Honda fluid and failed,  it was a mechanical design fault -  not the fluid
B : If it used Redline fluid and failed, it wasn't a mechanical design fault - it was the fluid.

Any so the nonsense spreads.