# Synthetic transmission fluids

**URL:** <https://community.cartalk.com/t/synthetic-transmission-fluids/49083>\
**Category:** General Discussion\
**Tags:** t100, toyota\
**Created:** [May 19, 2010, 9:16pm UTC](https://community.cartalk.com/t/synthetic-transmission-fluids/49083 "2010-05-19T21:16:41Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![nitram](https://avatars.discourse-cdn.com/v4/letter/n/5fc32e/32.png) [@nitram](https://community.cartalk.com/u/nitram)\
**Post date:** [May 19, 2010, 9:16pm UTC](https://community.cartalk.com/t/synthetic-transmission-fluids/49083/1 "2010-05-19T21:16:41Z")

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Toyota T-100, 108,000 miles. Have done several drain/refill using conventional fluids, and want to know of any potential problems/benefits with switching to Mobil synthetic trans fluid.

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**Author:** ![dagosa](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/dagosa/32/9837_2.png) [@dagosa](https://community.cartalk.com/u/dagosa)\
**Post date:** [May 19, 2010, 9:56pm UTC](https://community.cartalk.com/t/synthetic-transmission-fluids/49083/2 "2010-05-19T21:56:38Z")

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The problem I would have is that drain and refill does not replace all the fluid. So for me to use I would have to be really sure about compatibility. Have a heart to heart with a dealer service rep. and the exact fluids you have in and plan to use. I personal would leave with the same girl I brought to the dance. I see no advantage unless you’re towing, plowing or never plan on changing it again before you sell

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**Author:** ![mcparadise](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mcparadise/32/32_2.png) [@mcparadise](https://community.cartalk.com/u/mcparadise)\
**Post date:** [May 19, 2010, 11:58pm UTC](https://community.cartalk.com/t/synthetic-transmission-fluids/49083/3 "2010-05-19T23:58:12Z")

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Unless the owner’s manual specifies synthetic fluid, or you are using the truck for some REALLY heavy-duty work, I see no advantage in switching to synthetic.

Why are you thinking about switching?

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**Author:** ![Whitey](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/whitey/32/24680_2.png) [@Whitey](https://community.cartalk.com/u/Whitey)\
**Post date:** [May 20, 2010, 12:30am UTC](https://community.cartalk.com/t/synthetic-transmission-fluids/49083/4 "2010-05-20T00:30:24Z")

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If normal transmission fluid has worked well until now, why switch?