Size of fuel hose?

[dnguyen1963]

Hi,

Can you guys tell me the correct size for the fuel hose connecting the FPR and injector fuel rail to the fuel lines? There are 6, 8, and 12 mm ID fuel hoses...not sure which size would fit.

Thanks.

[phenobarb1]

I'm pretty sure it's 8mm. At least that is the size I think I used to run from the fuel pump forward, so I doubt the inner dimension would change further down the line.

[nando]

pretty sure it's 8mm

[jlevie]

Those lines are 8mm. 5/16" hose is almost exactly 8mm.

[dnguyen1963]

Thank you all!

[jlevie]

When replacing fuel hoses you must use hose rated for fuel injection service on the high pressure side. That hose is sort of pricey (~$6/ft) and you can save some money by using ordinary fuel hose for the low pressure side.

[jeffnhiscars]

At the Asheville gathering on Saturday BMWtyro (Jeff) gave a presentation on the effect of ethanol (gasahol) on normal "fuel rated" hose. Pressure rating aside, it seems that it is not chemically compatible with standard fuel line resulting in more and more fuel system related issues.

FI rated hose does not seem to have this issue and is at present the only type of hose BMW sells.

Just an fyi