DEXRON VI Alone Is Not a Mercedes W220 Fluid Approval

Do not choose transmission oil for a Mercedes W220 just because the bottle says “DEXRON VI” or “Dexron 6.” That identifies a GM fluid specification, not proof that the product meets your Mercedes transmission’s requirements. For a W220 with a confirmed 722.6 five-speed automatic, look for MB-Approval 236.14, as specified in the Mercedes transmission-fluid service bulletin dated January 23, 2018.

Mercedes recommends using fluids it has tested and approved, and says approved products are identified on their containers with wording such as “MB-Freigabe”—Mercedes approval. Check the exact product against the relevant Mercedes operating-fluid list.

Identify the gearbox before buying

This advice concerns W220 S-Class cars with a verified 722.6 transmission. Do not assume every W220 has that gearbox: the chassis also used the 722.9 seven-speed automatic. The W220 transmission reference distinguishes both families.

Use the VIN-linked vehicle data card and, where necessary, the installed transmission identification. Record the car’s year, variant and full gearbox number before ordering fluid, especially if the transmission may have been replaced.

Stop if the gearbox is unidentified. A search result for “S-Class transmission oil” is not a sufficient specification check.

What should a 722.6 owner look for?

The Mercedes bulletin specifies MB 236.14 for the 722.6 and explicitly excludes FE-ATF 134 and ATF D97. Those similarly named fluids are not substitutes. See the bulletin’s application guidance.

Fuchs also specifically recommends TITAN ATF 4134 for rear-wheel-drive vehicles with the 722.6 and lists its MB-Approval 236.14. Its application documentation says to follow the manufacturer’s filling instructions and avoid mixing with other oils to obtain the product’s full benefits.

On Mercedes’ 236.14 approved-product list, checked on October 8, 2026, products include Fuchs TITAN ATF 4134, Mobil ATF 134 and Shell ATF134. Match the complete product name, not just the brand or the “134” suffix.

For another W220 gearbox, verify its own application-specific requirement rather than carrying over the 722.6 recommendation.

“Suitable for Mercedes” is not the same as approved

A useful example is Mobil DEXRON-VI ATF on Mobil’s Singapore product page, dated February 2026. ExxonMobil recommends that formulation for numerous applications, including MB 236.10. But it explicitly says the vehicle manufacturers have not evaluated or approved it for the listed applications; its approvals section lists GM DEXRON VI. Read the exact product data sheet.

That is different from Mobil ATF 134, whose product sheet lists MB-Approval 236.14. Check the documentation for the bottle and market version actually being sold.

Bottle or data-sheet wording	Buying decision
GM DEXRON VI approval only	Does not establish Mercedes suitability
“Recommended for” or “suitable for” MB 236.10	Fluid-maker recommendation; not Mercedes approval
Applicable MB approval, with the exact product on Mercedes’ list	The stronger basis for selection

If DEXRON VI has already been added

Keep the bottle or receipt and record the product, quantity added, previous fluid if known, and any symptoms. First establish whether the exact fluid has the required Mercedes approval. The words “DEXRON VI” alone neither prove compatibility nor prove that damage has occurred.

Do not add more questionable fluid or start an improvised flush. Have the specification and level checked, then plan any correction around the installed gearbox. If the car now slips, fails to engage or makes unusual noise, stop driving and arrange diagnosis rather than testing it repeatedly. Active dripping together with those symptoms also calls for stopping, not another top-up and road test.

For a routine top-up, locate and repair the leak and use the correct level procedure; see W220 dipstick location and gearbox differences. Match the Mercedes approval first; treat DEXRON VI as separate information.