# Diesel additive **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [October 10, 2008, 9:25pm UTC](https://community.cartalk.com/t/diesel-additive/20589 "2008-10-10T21:25:44Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![dllind](https://avatars.discourse-cdn.com/v4/letter/d/2acd7d/32.png) [@dllind](https://community.cartalk.com/u/dllind)\ **Post date:** [October 10, 2008, 9:25pm UTC](https://community.cartalk.com/t/diesel-additive/20589/1 "2008-10-10T21:25:44Z")
A friend told me that if I add some transmission fluid to my diesel fuel tank, it would lube the injectors and help the engine. Any truth to this? ---
**Author:** ![the\_same\_mountainbike](https://avatars.discourse-cdn.com/v4/letter/t/c89c15/32.png) [@the\_same\_mountainbike](https://community.cartalk.com/u/the_same_mountainbike)\ **Post date:** [October 10, 2008, 9:44pm UTC](https://community.cartalk.com/t/diesel-additive/20589/2 "2008-10-10T21:44:40Z")
Have you read your owner’s manual? Do you somehow suspect that your friend knows more about what’s correct for your vehicle than the guys who, working with the specification documents provided by the deaigners, wrote the owner’s manual? I thought not. ---
**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:** [October 10, 2008, 10:08pm UTC](https://community.cartalk.com/t/diesel-additive/20589/3 "2008-10-10T22:08:25Z")
If it were true the engine manufacturer would recommend it, and your owner’s manual would tell you to do it. Is transmission fluid recommended as a fuel additive in your owner’s manual? I doubt it. ---
**Author:** ![jayhawkroy](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/jayhawkroy/32/33_2.png) [@jayhawkroy](https://community.cartalk.com/u/jayhawkroy)\ **Post date:** [October 10, 2008, 11:02pm UTC](https://community.cartalk.com/t/diesel-additive/20589/4 "2008-10-10T23:02:07Z")
There are special additives you can buy to this. Granted they are more expensive than ATF, but they are certified for use as an additive. Power Service is one. ---
**Author:** ![Joseph\_E\_Meehan](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/joseph_e_meehan/32/21_2.png) [@Joseph\_E\_Meehan](https://community.cartalk.com/u/Joseph_E_Meehan)\ **Post date:** [October 10, 2008, 11:33pm UTC](https://community.cartalk.com/t/diesel-additive/20589/5 "2008-10-10T23:33:13Z")
Did your friend tell you why you needed to lube the injectors? Remember that diesel is an oil. Also standard diesel fuel already has additives in it and for most diesel users, that is all that’s needed. A lot of people do add comerical additives to increase lubrication and they seldom have problems. Of course then there are many people like me who do not, and we seldom have problems. Check your owner’s manual. If it does not specify it, you really don’t need it. Note: some people became worried when ULSD fuel came out as sulfur does act as a lubricant. However there has not been any indication that it has created any problems and I would have expected that to show up long ago if there was a problem. ---
**Author:** ![Caddyman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/caddyman/32/23_2.png) [@Caddyman](https://community.cartalk.com/u/Caddyman)\ **Post date:** [October 11, 2008, 7:07am UTC](https://community.cartalk.com/t/diesel-additive/20589/6 "2008-10-11T07:07:24Z")
I have heard of big-rig truckers doing this, especially in old, tired engines. They claim a noticeable performance improvement. ---
**Author:** ![thecarguy](https://avatars.discourse-cdn.com/v4/letter/t/ea5d25/32.png) [@thecarguy](https://community.cartalk.com/u/thecarguy)\ **Post date:** [October 11, 2008, 9:07am UTC](https://community.cartalk.com/t/diesel-additive/20589/7 "2008-10-11T09:07:40Z")
it could be true, but why add that when you can buy the stuff made to do that at about the same price?