what is faster, or no difference?

[worldly oak]

given that all car models are stored in upper case in the database (postgres)
input may contain small letters (Ford vs FORD)

Car.object.filter(model=model)

or

model = kwargs["modelname"]
Car.object.filter(model__iexact=model)

[deft parcel]

when in doubt, use the SQL command EXPLAIN

but = usually performs better then LIKE (contains) or ILIKE(iexact or icontains)

[limber elk]

iexact will convert to UPPER in postgres

 WHERE "table"."foo" = 'value' -- foo=value
 WHERE UPPER("table"."foo"::text) = UPPER('value') -- foo__iexact=value