Option Explicit
'
Const mc_count As Long = 10 ^ 9
'


Sub MissOderVergiss()
    
    Debug.Print "implizit: " & getTimeImpli()
    Debug.Print "explizit: " & getTimeExpli()
    
End Sub

Function getTimeImpli() As Variant

    Dim i               As Long
    Dim t               As Variant
    Dim k               As Integer
    Dim q               As Double
    
    k = 432
    t = Timer
    
    For i = 0 To mc_count
        q = k
    Next i
    
    getTimeImpli = (Timer - t) & "/sek"
    
    
End Function

Function getTimeExpli() As Variant

    Dim i               As Long
    Dim t               As Variant
    Dim k               As Integer
    Dim q               As Double
    
    k = 432
    t = Timer
    
    For i = 0 To mc_count
        q = CDbl(k)
    Next i
    
    getTimeExpli = (Timer - t) & "/sek"

    
    
End Function

Ergebnis:

implizit: 16,26563/sek
explizit: 15,91016/sek