Spelling error should be Torquay

The Michelin website (http://www.viamichelin.com) suggests 3 hours 53 using M3/A303 and 4 hours 15 minutes using M4/M5, so a difference of about 20 minutes. In practice, it's going to depend on the traffic conditions on the day, and either route could be best. At present, there are major roadworks at the M4/M5 junction outside Bristol which could cause delays, but the A303 is also notorious for delays at times. You would drive past Stonehenge on the A303.

But why are flying to Gatwick? There are direct flights by Flybe from Dublin to Exeter, and also frequent direct flights by both Ryanair and Aer Lingus between Dublin and Bristol. Both airports are much closer to Torquay, and are also likely to mean less time in getting through the terminal.

Fly to Exeter.

I agree, fly to Exeter.

and why Torquay? on your other thread you are asking for recommendations for places to stay in Devon, and Torquay would not be top of my list.

plenty of nicer places in that area - Topsham, Salcombe and Dartmouth spring immediately to mind.

have a look here for good upmarket recommendations:

http://www.sawdays.co.uk/

or here:

www.visitdevon.co.uk

Assuming you've booked to Gatwick because Aer Lingus offers excellent deals, if you're in the car by 3.30 you'll be on the M23/M25 for a while whatever you do.

So check for hold ups on both routes before leaving home at http://www.highways.gov.uk/traffic-information/, and decide which seems to make better sense. Before leaving the hire place, make sure you've set the RDS system and (sorry, but I can't remember whether the system operates in Ireland: I couldn't get it to a few weeks back, but that might be me) you know how to use it.

If, before you get to the M25/M3 junction, serious congestion is announced on your prechosen route, use the other one.

But I agree with the others. I doubt the Gatwick deal really does work out cheaper, once you've paid the extra petrol, than a flight to Heathrow, Bristol or Exeter.