coolant temp CIS sender service life

[Jpinkowish at aol.com]

My mileage has dropped from about 22-23mpg to about 20mpg.

I notice my CIS temp sender is 3yrs and 40k miles old.

Is this a normal life for the sender?  I plan to measure the resistance 
output vs. temp.

Everything else important(O2 sender, plugs, wahres, etc.) is new or <10k 
miles old.

I also confess that central CT is now cold and now has ethanol in the gas.  
But the mileage drop began before the pump/gas switch and the seriously cold 
weathah.

Jan Pinkowish
'85 4ksq
Ethanol, CT