Oil press sensor thread..?

Both are pipe threads, NPT= National Pipe Thread NPTF= National Pipe Thread Fuel. Both will work same threads, but NPTF will have longer threads. This is usually use in fuel systems for a tight fit without the use of sealants or tape. I would use the 1/8 NPF sender but if the threads are wallowed out this where the NPTF sender would be a big help......