Hello

thanks for your response, 

+odoo restart , Tested OK, thanks !

I see that affects also all unit-prices (products, etc..) , not only the price per KM, But we can live with that. 

The problem is that the 2 decimal rounded is used for the expense calculation.
ex : when the price per km is entered and seems stored at 0.687€/km, the calculation for 100km is  70€ (and not  68.70€)

if you can advise...
Luc

Hi,

First, activate the developer mode, then navigate to Settings -> Technical -> Database Structure -> Decimal Accuracy, here you can see a record named Product Price, open it, and change the value of digits to 4.

Hope it helps,