hi supeerman - welcome to the TDR.
you will get varying opinions on this issue. my take is that there is no advantage to doing this.
first off, kerosene has less lubricating value than diesel fuel and could shorten the life of the metal to metal components of the pump and such. obviously this is relative to the percentage of kerosene you put in.
depending on where you are located (please fill out your profile and signature), if it is really cold, like 0 degrees F, you could thin with kerosene about 10% (in an emergency) just to keep the fuel flowing. otherwise there are specific purpose additives to help low temp flow.
if you do a search on "fuel additives" you will probably find many threads on this issue.
in conclussion, don't add kerosene - save it for the torpedo heater.
once again, welcome aboard and let us know what you are driving!
jim