Tax relief on employee subsidising company car?

FLB_Francaise

In my work I get a car allowance of £x but you can get a car for a higher monthly cost if you pay the excess out of your net pay.

On the basis that I'm getting an Electric Car, with a low BIK rate, can I treat these extra payments as allowable expenses on my Self Assessment? 

I can't see the difference between a car allowance and actual salary in logical terms, so it would seem strange that one gets relieved from tax and one does not?

uknick

As an employee, expenses can only be reclaimed if they are wholly, necessarily and exclusively to do your job.  I assume the car has personal use as well as business use, in which case it would fail the wholly & exclusively tests.