we want to be at heathrow airport at 8 AM.

If leave hotel by limo (arranged car - not really a limo) at 7 AM. should we be there by 8AM? this is on a monday morning.

(don't suggest underground or buses - not workable in our situation)

thanks

Ask the car service. They do this every day - Fodorites only occasionally.

The ride from central London typically takes us about 40 minutes in the early morning. I can highly recommend Ray Skinner of London-Transfers.com. We've used him many times and have been very pleased. Check with him about your timetable.

Tell them you need to be at the airport by 8AM, and let them work out when you need to be picked up.

Monday morning at Heathrow is a rush hour, esp if you're flying out of T1. (Lots of business-wallahs taking the first flights to the continent for meetings). 45 min would be quite tight, more like 60min... Also depends on which part of London you'll be originating from.
I second asking the car service company. You'll need to tell them which terminal you're going to.

We have used Ray Skinner many times and it's never taken more then 45 min. -- however it can as anyone who lives where there is traffic can tell you. Ask your car service if one hour is enough time. Frankly if it were me I'd ask for 6:30 pickup "just in case" but that's just me

Another good service is www.justairports.com. You can bet the service provided by the hotel will be a lot more expensive, since they will get their piece of the pie.

I have also used Ray Skinner a few times- EXCELLENT service- on time- etc.
Make sure you get there early enuf with rush hour travel and also the 2 1/2 hr check in for International travelers...

We were also pleased with justairports. They are very reasonable and can advise on the best time to leave.