MB uses both 7.5 & 8 mm fuel lines. Most part stores have 5/16" that is very close. MB suggested list for a meter of the factory line is $12. (916030-000527) is the part number

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator