I put M1 ATF in our Accord 5AT. Did a complete flush and havent looked back. The Accord shifted so smooth it was doing its best to be a GM slush box. The M1 firmed the shifts up a tad. Also droped my tranny fluid temps a hair messured with my fluke and temp prob zip tied to the dip stick. When a AT shifts buttery smooth its waisting hp, energy and makeing more heat. All of which are very bad IMO.
Every thrid oil change I drain 3 qts of tranny fluid and replace the tranny filter and fluid.
If Honda does the up coming Accord Hybrid right we mite trade our Accord EX. But Im not holding my breath. I can see rear drum brakes and a CVT. The rear drum brakes would kill the deal. If they only offer a CVT ,, o well. It will be the wifes car and shes lazy and dosent like to shift gears.
So in the meantime. I will keep the fluids and filters maintained and the shifts positive. ( not harsh )
SVO
The grinding and syncro problems are almost soley in the 6MT's in Hondas line up. I havent heard of any 5MT problems in late model Accords or Civics. Just TL, TSX, Accord and Si.
IMO alot of the problems folks are having are brought on by the owners. I see so many folks that back a car up and before its stoped there craming it in 1st gear to the tune of complaint from the gear box. My Civic and Ranger both compain about doing that. Then there are the folks that blow afew shifts going into 2nd or 3rd at high rpm's and loads. Then a few weeks later. Darn,, 2nd or 3rd gears are now goofy. The 6MT's seem to not be quite as strong as a 5MT.
As trannys get more complex and fragil they need far more mait. IMO. Its ubber cheap ins.
I also did a flush on the Civic's 5MT when I did the 1st oil change. I put Honda MT fluid back in it after I flushed it with a cheap 5-w30. Next oil change its going to a M1 oil. Just havent decieded yet which one.