It would be hard work to change the engine sound, so it better be an eight cylinder engine. 
Posted by: Wendax
not at all - location sound is almost never used - instead everything is fabricated after cutting picture.
a good sound recordist will get what they can from a shot as a guide track and after 'cut' or before leaving the set or location call for quiet and redo the lines, actions, effects and atmosphere - ambient sound - if possible but most actors expect to give a vocal performance at a later date which is mixed in with what the editors have assembled. afaik.
Accepted, I just needed a reason for a hint quickly
Posted by: Wendax
Accepted, I just needed a reason for an article finally
As far as i know the trend in the last twenty years is for 'location' sound to be rarely used - rather fabricating everything after cutting picture. Apparently modern actors expect to give their vocal performance at a later date, mixing in to what the editors have assembled. This is despite the technology making recording sound on a film shoot much easier than when reliant on cables for miking and clapper-boards for sync.
However, even if their efforts are just going to be considered a guide track, a good sound recordist will be trying to get whatever they can from a shot and then, asap after 'cut' - or at least before leaving the set or location - call for quiet and - as best as possible - record 'wild' the lines, actions, effects and a long clean 'atmos' (ambient sound). The hero vehicle (if not as cheap-looking as the one in question) should also be commandeered for an exhaustive documentation of its sound; ideally both interior and various exterior perspectives of start-up, idle and switch-off, various speeds of running / passes on paved and gravel etc., keys, controls, brakes, doors, upholstery squeaks, certainly everything that might have been seen on camera.
All of the above can recreate sound that complements the picture and loses the otherwise inevitable distractions; off-camera noises, changes between set-ups, traffic or - once upon a time - just the sound of film camera shutter and magazine (of course this too is a thing of the past and the editing process is no longer so much like carpentry; butting and splicing sprocketted strips to pass magnetic heads and ultimately an optical reader at 24 or 25 frames a second, physically removing a single frame where a vowel in the middle of a word goes on too long to be fitted in to the lips on screen, scraping oxide off the film to fade out volume if necessary ...).
Dealing with the likes of this particular hero vehicle, the post sync sound effects or foley editor/s will have gone out and recorded or referred to library stock to contrive something that hopefully didn't sound too wrong for the all-important 'suspension of disbelief' in the audience. Someone will have said; 'if they spot that, they're not watching the movie', in this case, probably the art department.
Sound editors could err too of course; post-production on Alice to Nowhere (a miniseries set largely in a cross country truck) somehow while recording a big Volvo in a quarry no-one had noticed it was an auto ...
As for hard work, never came closer to having fun and getting paid for it. Sometimes both at once, too.
One memory though; being left alone in the studio with a 7in spool supposedly copied from one recorded for Empire of the Sun; (and recorded perfectly) - just a lone P-51 working through that kind of list in a silent valley somewhere; high and wide, low and fast past ... best thing i've ever heard ... hope it was a real Merlin.
steven
