3 weeks traveling in Europe 3 adults, 2 almost teens, rent or lease a car or combine car and train

Try kayak to get price comparison for different car rental companies, sizes etc. at the same time, You can punch in places and dates for pickup and dropoff.

After you use kayak, you can then try booking directly with the car rental website to see if they offer a better deal. I usually find that booking for a full week is cheaper than booking 5 pr 6 days. And picking and dropping off at a major outlet like the airport or train station may be cheaper than a neighbourhood outlet or hotel. Not that this helps you because you have already set out your direction of travel, but there is a price diff depending on which direction you travel. For example, i found picking up and dropping off Venice to Rome to be much cheaper than Rome to Venice.

My dad usually leases a car, he has used Europcar..

Note cars are smller so with luggage you will likely need a van or some such large car..gas is EXPENSIVE and there are tolls to include in your projected budget.

Using trains is usually a better option for European travel. Trains are faster for long distances - high-speed trains cruise at double the speed of a car and don't stop for traffic. They are more comfortable for long trips than being crammed and strapped into a car. When you are staying in cities, you will pay a lot for parking in the center or spend a lot of time commuting on public transportation. You will pay for toll roads, expensive gas (probably double what you pay at home) and "vignettes." Use viamichelin.com to estimate driving times and costs to get an idea of how much it will really cost you. Eurail passes are generally not the cheapest way to buy train tickets.

If you are starting in Rome and ending in Paris, with 3-4 days in each, that leaves you with 2 weeks to see Italy, Austria, Germany, Switzerland and France by car, not 3. There is usually a stiff drop-off charge for a returning a car in another country. Consider the size of the car you would need. You will be traveling with 5 people's luggage. When you park the car en route, you don't want to leave any belongings visible in the car, so you need one big enough to hold all the bags in the trunk. Larger vehicles will be harder to drive on back roads and villages and will use more gas.

You didn't ask, but I have to say that you are looking at an unrealistic trip. This would be an ambitious itinerary for a guided tour, with a driver who drops you in front of your hotel and then parks the bus, and with a guide who knows every stop and leads you to the top sights and skips the waiting lines. One and two night stays are tiring, so are long stretches in a car. Are you planning to visit cities or stay in outlying villages? Do you want major sights or days of scenic driving? What's your proposed itinerary?

I agree that this is a somewhat difficult itinerary, especially for 5 people. You would require a van, and vans are quite expensive to rent or lease. And the rental car companies will charge an enormous drop off fee if you leave it in a different country.
I would suggest you fly into Rome and work your way north by train. Point to point tickets are the way to go, and you can buy them at a great discount ahead of time. If you want to see the countryside, then rent a vehicle to do day trips. Then take a train to your next location.

It's easy to get into Austria from Italy via train, and you can get your fill of the mountain/alp scenery there. In other words, skip Switzerland as it's also very expensive to visit there. You might do best to stick to visiting Munich and Bavaria for your German leg of the trip.

I'm big on combining train travel and budget European airlines--and avoiding very long train rides whenever possible. You might see about catching a budget airline over to Paris if available. If not available, take a train.

"We want to experience as much as possible as we travel and would like to travel by car."

Like the others above, I would urge you to reconsider the train option.

Trains allow you to enjoy the scenery in a roomy environment - with no parking fees or tolls, no potty stops or fill-ups, no rental contracts, no traffic, no draining driving responsibilities for the driver. You can chat, nap, strike up chats with other travelers, have a mini-picnic, read your guidebook or a novel, pretty much do anything you like.

Did you look into the German Rail Pass? It's good for all of Germany of course - reservations are not required there - but also to/from several destinations in ITALY, including Venice. It's also good for some of AUSTRIA. I have no idea how many days of travel you would need, but for 3 weeks, you probably shouldn't have more than 7 changes of location (thus 7 travel days.) Perhaps a 5-day German Rail Pass (2 twinpasses and 1 youth, for example, €836 total) would cover most of your journeys - then you buy saver fares for the other two journeys.

I agree with the others as well that your itinerary is likely too aggressive.

Once my family (wife and kids) kicked the rental car habit and jumped on the train there was no looking back! Trains are SOOOOO much more enjoyable in every way. They usually go wherever you need to go. Sometimes we do flag down a taxi to transport us with luggage (very rarely), but there is just no travel comfort like the trains.

Do NOT fall sucker to the Eurail Pass. Just buy point to point tickets especially in Italy. In Switzerland get a Half Fare Card for the adults and free Swiss Family Passes for your kids (they'll travel everywhere free with you) and that will save you an unbelievable amount of travel $. From Rome/Venice -> Paris just fly on EasyJet.

We take teenagers to Europe every year and we've got this travel thing down pretty well by now. And even before those trips we took our own kids all over Europe for several years. We've been there done that and learned from our mistakes. Hopefully you can learn the "easy way" through us.

We love to rent a car to get off the beaten path and be on our own time schedule. It is our favorite way to travel. We rent in one country and loop around to return the car in the same country or rent two different vehicles or whatever we need in order to return it to the same country to avoid fees. We also travel with 3 people. You really don't do not want a car in Rome, Venice or Paris and with 5 people and luggage it will be nearly impossible except for getting a small van which will be expensive and harder to drive on the small roads.

If you have a home base while in the countryside maybe you can rent a car for a couple days leaving your luggage at "home". I don't think you will be able to move from place to place with a rental car, 5 people and luggage. Cars are smaller in Europe and so you have to make sure you understand the size of the car before you rent one.

I'll never forget watching a family- parents with two teens- trying to get themselves and their luggage into a rental car. They had obviously never been to Europe and each brought large suitcases. I was laughing hysterically from a distance! They ended up with luggage on their laps in the back seat and when they took off the people in the back seat had luggage from their laps to the top of the roof of the car! They couldn't see a thing. It was quite a sight!!

You might want to look up all the train travel and see if it is cheaper to buy tickets point to point vs. a Eurail pass. Often this is the case.

Ditto to what Russ said. You really have to look at your itinerary and see if you need a car. If you're going city-to-city, it's much smarter to take trains (and no you do not need a Eurail pass). In fact, a car will be a hindrance, and renting in Rome and dropping off in Paris will cost an arm and a leg for the drop off fee alone (not to mention the cost for a vehicle large enough to take all of you, plus the fuel, plus the tolls, plus the parking fees in whatever cities you're in).

If you want to explore the countryside in some places, you could rent a vehicle for a day or two as necessary. But it really depends on what your basic trip plans are.

While it is often said that leasing is better if your rental period exceeds 3 weeks, the times we've looked into leasing, renting came up cheaper. I think you have to get significantly past the 3 week cut-off for leasing to be cost effective. Also, while it's true that the leasing price includes insurance, picking up or dropping the car outside of France incurs a substantial extra cost - - $400 when we checked. If you go to AutoEurope.com or Kemwel.com you can put in your information and get prices. I'm inclined to join those who advise trains.