gas and tolls

Yes, euros.

We are just back from a lot of driving in Italy. Gas stations just like the US are everywhere and often offer both self service and attended. The attended was always a few pennies more so we opted for the service. We also had a diesel car and that fuel is more messy. They always took our US credit card with no problems. As far as toll roads we always make sure we had plenty of cash. Again, most were attended but once had to feed the money into a machine. It worked fine. You do not deal with euro conversion at filling stations or toll booth. It is all local currency - Euro. The one small problem we hit was on a Sunday morning returning to the airport, a lot of the smaller stations were closed.

I can't emphasize enough the importance of not letting your gas get too low; and/or keeping a supply of cash on hand. You may encounter unattended stations on weekends or at midday (noonish to 4 p.m.). Your American cc will probably not work. Ditto for an occasional toll booth. Even at attended stations where they are displaying the cc logos, you may encounter the oft-employed Italian scam of claiming the cc machine doesn't work. They are either cheating on their taxes, or don't want to pay the commission. We have experienced all of the above. Toll booths will display the amount you owe. It's easy to count out exact amounts or to check that you received correct change. After all, it's a decimal system, and the coins' values are marked on them. Never had a problem with a tollbooth attendant. While we're on the subject of tollbooths, be sure, as you approach, that you're not in a lane for electronic passes (akin to our fastrak or e-z pass) only. The icons are fairly self-explanatory.

Rosalyn,
Thanks for your advice. When people I post with say "cash" I'm assuming it means euros?John

I can't imagine that you'll find any service stations that would accept anything but euros, and certainly not any toll booths. The only places in Italy that might accept other currencies would be at extremely touristy sites, and they would give you a BAD exchange rate. The exception might be at places close to international borders. For example, we were staying in the Lake Maggiore area and went to Locarno for the day. The restaurant we ate at accepted CHF, euros, and USD; but I'd never assume that that would be the case.

Euros are the only legal tender in Italy. In a few areas with lots of tourists (including airports), you may encounter a store that will take US dollars, but remember the following: -They are under NO obligation to take foreign currency. -They can set any exchange rate they want, and it will usually not be a good one.
-You will get change in euros. Gas stations in Italy will be as eager to take US dollars as those in the US are to take euros. In other words, it's euros or nothing (whether you use cash or credit card, you will be paying euros). Get used to thinking in euros. To find exact exchange rates, use http://www.xe.com or http://www.oanda.com. But for gas (and indeed for most things), all you need is an approximation. Right now, it's approximately 1.33 dollars per euro. So, just add a third to the euro price to get the approximate dollar equivalent. That means 30 euros is about 40 dollars. Here's a page of Rick's excellent money advice. Read all the links, and you'll be a pro: http://www.ricksteves.com/plan/tips/money-travel-tips.htm

You might want to check out this website. http://www.slowtrav.com/italy/driving/index.html

John, everyone here has given you EXCELLENT advice. Don't even think about using US dollars for anything. (You can keep a couple of hundred in reserve, but that is more than enough) You will need Euros in all "small" places, and your credit card will work just fine elsewhere. We never bring Euros with us. As soon as we get off the plane we walk up to a bank owned ATM and pick up at least $200-330 Euros. ATM's are like Italian wine; you will find them everywhere! The price of fuel is usually around $8-10 gallon (approx.) Get a diesel car! At 40-50 miles per gallon you will come out way ahead of the game. Bring your GPS from home, a Michelin map of the Country, a compass, your divers license, and the International Driers Permit that you buy at your local AAA office. Make sure that you exactly what a "ZTL" is. If you drive into any city with one of these your pocket book could be in peril, unless you stay away!

Gas stations work like in the US. However at night (from 7pm to 7am generally) and between 1 and 3 pm (and Sundays all day) they are totally unattended. That means that if you need gas you must use the automatic machines to get gas using either credit card or cash. Rent diesel, if you can, as others have pointed out you will get at least 18km per liter (about 45 miles per gallon). There are 3 types of Toll booths on Freeways: TELE PASS - don't go here, you need a transponder CARTE - you can pay with credit cards or Via Card (a prepaid card that you can purchase with whichever denomination, the toll is deducted from the value of the card).
CASH SYMBOL - cash only.