Oil Fill Management - Rented Property

Apologies for this mundane problem but not sure how to proceed in this case.

New property with oil fired central heating. Wondering how to manage oil fills between changes of tenants. Should I as Landlord purchase the oil and get a gauge to monitor it and include an approriate amount in deposit for doing this ? Or, should I let each incoming tenant be responsible for their own oil fill ?

My problem with the second scenario is the case where a tenant leaves with plently of oil left in the oil tank. Are they entitled to money back from the Landlord in this case ?

I would appreciate any suggestions from people who are in similiar situation.

The tanker driver gives you a slip with an opening balance(reading) and a closing one.

Make sure tank is full when you give it to tenant (show proof of fill), and insist tank is full when they leave.

If you ever hired a rented car ... same scenario.

or market the rental with free fill of oil......have done this a few times and it certainly increases the amount of replies.
with careful management of viewings and offers you end up with higher rent than you hoped.
I have found the same with offering free broadband.

Or you could do the opposite - not get involved.
The tenant can have whatever's in the tank from previous tenant and if they leave too much when they go, it's their lookout.
Spell it out in the beginning or include it in the lease.