There’s confusing information in the Manuals regarding what hydraulic fluid should be used in Ducati forks.
Shell Donax TA should only be used in Showa forks.
Shell Advance Fork 7.5 should only be used in Ohlins forks.
The Ducati Owners Manuals and Workshop Manuals fail to make this distinction. They suggest that these two fork oils offer equivalent damping properties. They don’t. They have significantly different viscosities.
Here are the fork manufacturers specified products for Ducati forks.
Showa — Suspension Fluid SS-08 (10 Wt): Measured 36.5 cSt @40C
(Note: Pro Honda SS-8 (10 Wt) Fork Oil is the same fluid)
Ohlins — Front Fork Fluid 1309 (9 Wt): Measured 19.0 cSt @40C
Compare Viscosities:
Shell Donax TA: Measured 34.9 cSt @40C
Shell Advance Fork 7.5: Measured 22.0 cSt @40C
It’s probably WISE to let the fork manufacturer be the final arbiter of what formulation of hydraulic fluid should be used in their product.
Ohlins and Showa are in the best position to evaluate material compatibility issues and have extensively tested their fork seals with their hydraulic fluid that they have specified in the their product literature. This is not to say that fork oil from another manufacturer will result in damage to the fork seals, they simply haven’t been tested by the fork manufacturers for long term compatibility with their particular seal material.
There is are significant differences in fork fluid hydraulic properties from different manufacturers so you can't just buy any equivalent weight fluid and get the same damping behavior intended by Ducati, Ohlins or Showa.
Over the years, Ducati has changed the Manual's recommended fluid for Ohlins and Showa forks. AGIP was specified before Shell. Of course, AGIP was the sponsor for Ducati racing activities before Shell took over — so it's no surprise to see only Shell Products recommended in the present day Owners and Workshop Manuals.
Shell Donax TA should only be used in Showa forks.
Shell Advance Fork 7.5 should only be used in Ohlins forks.
The Ducati Owners Manuals and Workshop Manuals fail to make this distinction. They suggest that these two fork oils offer equivalent damping properties. They don’t. They have significantly different viscosities.
Here are the fork manufacturers specified products for Ducati forks.
Showa — Suspension Fluid SS-08 (10 Wt): Measured 36.5 cSt @40C
(Note: Pro Honda SS-8 (10 Wt) Fork Oil is the same fluid)
Ohlins — Front Fork Fluid 1309 (9 Wt): Measured 19.0 cSt @40C
Compare Viscosities:
Shell Donax TA: Measured 34.9 cSt @40C
Shell Advance Fork 7.5: Measured 22.0 cSt @40C
It’s probably WISE to let the fork manufacturer be the final arbiter of what formulation of hydraulic fluid should be used in their product.
Ohlins and Showa are in the best position to evaluate material compatibility issues and have extensively tested their fork seals with their hydraulic fluid that they have specified in the their product literature. This is not to say that fork oil from another manufacturer will result in damage to the fork seals, they simply haven’t been tested by the fork manufacturers for long term compatibility with their particular seal material.
There is are significant differences in fork fluid hydraulic properties from different manufacturers so you can't just buy any equivalent weight fluid and get the same damping behavior intended by Ducati, Ohlins or Showa.
Over the years, Ducati has changed the Manual's recommended fluid for Ohlins and Showa forks. AGIP was specified before Shell. Of course, AGIP was the sponsor for Ducati racing activities before Shell took over — so it's no surprise to see only Shell Products recommended in the present day Owners and Workshop Manuals.
