[DeTomaso] Any Issue with using an Oil Pressure Gauge for Fuel Pressure???

[Ken Green]

The very cool MSD gauges being sold for about 1/4 retail include a 100 PSI oil pressure gauge.  Is there any obvious reason why it couldn't be used as a fuel pressure gauge?  I know gas is a LOT thinner, but hot oil seems like an even worse environment.
 
If necessary, I've seem hydraulic isolators to separate gas from a non-volatile liquid so the gauge can be in the cockpit, do I need one for this?
 
Ken