Don Muang to Suvarnabhumi
 

I have a domestic flight from Phuket to Bangkok (arriving at DMK at 15:00 on Friday) followed by an international flight from Suvarnabhumi (departing from BKK at 20:30 on Friday). I have 5.5 hours to get from DMK to BKK provided the Oriental Thai flight is on time. I figured if the flight is 2-3 hrs late + travel time between two airports (90 min) should still leave me about 1 hr before departure.
But am wondering whether I should come to Bangkok a day earlier?
Any one else has any experience with Oriental Thai being on schedule and traveling time between DMK and BKK on Friday evening.

You've got nothing to lose by going to Bangkok a day early. You will have a chance to do some last minute shopping cheaper than Phuket. Even have a hotel and local transportation cheaper than Phuket too. So you save a little money there too!

If the plane is on time you should have no problem getting to Suvarnabhumi by taxi on time for the next flight. But if it is late or even breaks down or is cancelled you lose your flight home.

veg.. 90 minutes driving time from DMK to BKK and worst case scenario 120 minutes. Orient Thai? One of the few airlines that I will not fly!

Better point out that the normal non rush hour driving time is only 30 - 45 minutes.

The transit time between the two airports is manageable, so an overnight in Bangkok shouldn't be necessary. But, you may have less stress if you give yourself that extra day to explore the city.

Either way, a couple of suggestions: opt in for the travel insurance which is offered by the airline, in case there is a flight delay or cancelation ($5 or so); do an online check in for the international flight, which will save time at BKK.

Welcome to Fodors terrawest.

I do believe that travel insurance will not cover low cost airlines for flight cancelations and delays. I'm probably wrong but so perhaps you can post some links?

Thanks everyone.
From my preliminary google search, I found that travel insurances have a grey area about missed connections. For my peace of mind, I changed my booking and decided to come a day earlier to Bangkok.
I had 4 tickets and so paid about $65 to make the change. So yes, if terrawest or anyone can share some information on travel insurance that you can add this clause to for $5, that would be useful to everyone.