I'm preparing to install a pair of low cost boost and oil pressure gauges for my '04 R53.
The gauges come with nylon tubing which I'm really not interested in using do to possible heat or failure.
I've used copper tubing for my oil pressure gauges many,many years ago. However given the plastic vacuum nipple connection for the boost gauge...I'm thinking silicon would be best.
I wouldn't think silicon would collapse or expand under vacuum/boost(?)
Has using the nylon tubing (of course routing away from hot components) posed an issue in your experience?

Your insight/recommend for heat tolerant boost and or oil pressure lines are very much appreciated ?

 

Use Copper for the Oil PSI because of the amount of heat in the area of the tap in connection. (Oil sending unit)

 

Yep.
Went with copper (again) for the Oil Pressure gauge. Remote set up w/a 3way brass hub = feed line, pressure gauge and factory pressure sending switch. Mounted nicely to the ABS "firewall".
1/8" ID x 1/4" OD silicone tubing for the Boost.

Edit: I originally had 90% of the 3way junction/hub components in stainless. I couldn't get the 1/8" x 3/8" OP coupler. I don't like brass - but I also don't like mixing metals. ALL brass had to do for now.