Recommended Transmission fluid

[Tristan8260]

I have a 2018 GMC sierra slt plus with the 8 speed transmission. Is the dextron 6 alright to use or do I need to use the dextron-HP.

[swathdiver]

1 hour ago, Tristan8260 said:

I have a 2018 GMC sierra slt plus with the 8 speed transmission. Is the dextron 6 alright to use or do I need to use the dextron-HP.

 

8-Speeds take Dexron HP

[CamGTP]

[WT35002017]

Amsoil Signature Series is what I use in my 6L90 and it also qualifies as Dexron HP.  I definitely recommend it, my transmission ran cooler and shifted smoother immediately after filling with it.

[WT35002017]

Amsoil Signature Series is what I use in my 6L90 and it also qualifies as Dexron HP.  I definitely recommend it, my transmission ran cooler and shifted smoother immediately after filling with it.

[Sir Dan]

Mobil 1 HP Blue Label is the only fluid recommended for the finicky 8 speed. Even with this fluid they are prone to torque converter shudder and harsh/delayed shifting. Gotta be the worst transmission GM ever dumped on us poor folks...

[diyer2]

Any fluid that meets spec will do. Mobil 1 fluids don't impress me. The Amsoil line has 3 products or another 100% synthetic like Redline.

[Black02Silverado]

AMSOIL's ATL transmission fluid would work great in the 8sp. 

 

Use AMSOIL Signature Series Fuel-Efficient Synthetic ATF in
transmissions and other applications that require any of the following specifications:
Aisin-Warner AW-1; BMW 83 22 0 142 516, 83 22 2 152 426; Chrysler MOPAR*
68157995AA, SP-IV, 68218925AB; DSIH 6p805; Ford MERCON* LV, SP, ULV; GM DEXRON*
HP, DEXRON* VI, ULV; Honda/Acura DW-1*, Type 3.0; Hyundai/Kia SP-IV, SPH-IV, SP-IV-
RR, NWS-9638, SP4-M; JASO 1A-LV; JWS 3324; Mazda ATF FZ; Mercedes Benz 236.12,
236.14, 236.15, 236.41; Mitsubishi SP-IV, ATF J3, ATF-PA, ATF-MA1; Nissan Matic-S, Matic-
W; Saab 93 165 147; Shell M-1375.4, M-1375.5, M-1375.6, M-L 12108; Toyota WS; Volvo
31256774; VW/Audi G 055 005, G 055 162, G 060 162; ZF S671 090 255.
AMSOIL Signature Series Fuel-Efficient Synthetic ATF is
backward compatible and replaces DEXRON III fluids in older GM
automatic transmissions. (DEXRON VI specification supersedes the
obsolete DEXRON III in GM vehicles.) Also suitable for Toyota CVT
applications calling for the Toyota “WS” specification