Im needing new Fuel hose inside the engine bay. Mostly the line to the fuel rails. Will 5/16 work on everything in there. I see it is all 3/8 right now but it seems to fit loose. Thanks

7.5mm I.D. is what you want not 5/16 definately not 3/8.. fuel pressure rated hose only. Seriously it may not seem like much or a big deal, until your car catches fire..

I use 7mm I.D. Contitech from Pelican Parts...

http://www.pelicanparts.com/cgi-bin/ksearc...-1-469-781-M149

Ok. Thanks. Yah the 3/8 hose is not right must have been all the previous owner could come up with. Thanks

Shameless plug: GPR set me up nicely with fuel line including the reducer if needed...

GPR

I probably should know what GPR stands for but I will ask anyway. Who is GPR. Thanks guys.

Get 7mm metric hose. 5/16" is almost 8mm. It will leak.

GPR is German Parts and Restoration.

Cool, Thanks

actually 5/16 inch works fine on our rides. you may want to specifcy the new hoses that is now introduced for the oxygenated and alchohol fuels mandated in many areas. these new fuels will harm most standrd fuel hoses (and other rubber bits) becuase of this a new type of hoses has been introducedsome years ago. It is the latest standrd for fuel injection motors (and is the only lawfull replacemnet hose to keep emmission legal on new cars)

the new hose has a teflon like liner inside, that resists the new fuels. the hoses with the liner has an SAE rating of 30R9 (the old non-lined hoses is 30R7) the new hose will resist the corrosive effects of the new fuels and helps fight smog becuase it is over 30 times less permiable to gas fumes that teh old SAE30R7 hoses.

as pointed out, you need to run the correct solid band hose clamps, no perferated clamsp as teh rubber can squeeze thru teh holes over time hence losseening the clamp


i have used the 5/16 inch hose for over a decade with no failure with hose clamps.

I have been unable to find the lined hose in metric but teh 5/16 inch works great. and will out last the standard hose. the linner will not dry out and get brittle and will prevent the rubber outside from getting in contact with the fuel, thus giving the hose a much much longer life, even with todays horrible fuel mixes.

Since all the fittings really are 8mm and have barb or beaded ends it will not leak when good quality new (F.I.) 5/16" (7.9mm) hose is used.

might as well then buy the correct hose for oxygenated fuel and get the 30R9 standard lined hose.

..........What drives me crazy with the O.E.M. fuel line hoses is the fabric outer liner... To me this is just a place for dirt, crud, OIL, and GASOLINE to accumulate/saturate.....on the way to starting a fire. I use 5/16 inch F.I. rated rubber Hose which has a smooth, easy to check and clean outer surface....mainly however for CARBURATORS.....properly making O.E.M. F.I. lines, especially to the injectors should be done by Your Porsche mechanic who has experience, and knowledge.