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Diesel fuel – adding lubricant

Excavator jay · 2019-12-31 23:28

Anyone tried adding tranny fluid to diesel fuel to add more lubrication.

Replies7
  1. #1Ronsii2020-01-01 00:38

    People have done it for years and years.... not sure if it really helps/hinders much but you know how these myths get started one guy says red fuel 'runs better' or 'red fuel has more power' and all of the sudden it's gospel I guess they missed the part where it comes out of the same spigot in the refinery and the guy adds they dye to it...

  2. #2Nige2020-01-01 14:56

    There is a standard for test for diesel fuel lubricity - ASTM D6079. It is measured by creating a "wear scar" on a test rig using a sample of the diesel as a lubricant. The maximum size of wear scar permitted under the standard is 520 microns. In days gone by the level of sulphur in the diesel provided as much lubrication as was required (and more besides) to keep injection system components happy. With the advent of Ultra-Low Sulphur diesel (ULSD) the subject of lubricity has been front and centre. Provided the fuel you are using meets the minimum lubricity standard in ASTM D6079 IMHO there is no logic in adding extra lubricant. As a comment most fuel out of refineries these days analyzes somewhere around 300 microns in wear scar size.

  3. #3RZucker2020-01-01 15:13

    This will explode some heads on the Diesel pickup forums.

  4. #4Nige2020-01-01 15:18

    Hand grenade pin pulled - ready for launch...............

  5. #5Excavator jay2020-01-01 15:19

    With the admin of ULSD 15ppm this old timer has a diesel tank he adds transmission fluid to it, not saying it’s right or wrong just wondering if anyone else has dealt with the ULSD this way. The new fuel injection systems would like the added lube. The old timer runs about 15 tractors and few loaders, doesn’t have to many issues we hear of.

  6. #6Nige2020-01-01 15:24

    FWIW the contract with our fuel supplier (major oil company) requires a maximum wear scar size of 400 microns. I haven't seen analysis yet where the figure was over 320. You could quit doing it and you still wouldn't have issues, because the fuel injection systems don't need any more lube than is already present in the fuel. My 2c, YMMV. We have over 100 pieces of equipment in our fleet and I cannot recall a single case of a seized injector or injection pump problem with using fuel "as is" straight from the supplier.

  7. #7Truck Shop2020-01-01 16:28

    Agreed,------ ATF, hydraulic fluid and 10wt motor oil is just some of the wives tails about about adding lubricity to diesel fuel. I'm surprised some ### wipe hasn't come up with adding 3 & 1 sewing machine oil. One of the first things to start was the ULSD was causing bonnet seals to start leaking when it first hit the market on Cat injection pumps. {It didn't leak until I started using the ULSD}. Never mind the pump had 900,000 miles on it.