I would say 10 years at least, MB uses a good hose. I changed all of the original 17 year old hoses in my SDL last spring. They were fine I probably could have gotton a few more years out of them.

I will do the upper hose every 5 years because it is very cheap.

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2006 CL500
2009 C300 4matic
1969 280SE
2023 Ram 1500
2007 Tiara 3200