Santorini - ATV questions

I have a somewhat strange question, but I'm hoping SOMEONE can answer it! We rented a three-wheeler (I think - one of those ATV things) when we were in Santorini before. My husband loved it (and with it, you don't need an int'l driver's license, which is a small plus). He wants to do it again, but the one we had before was underpowered and climbing up the hills (for example, to Oia) was a little slower than we found ideal. I don't know what cc it was, but now I'm looking at what's available, and wondering which one to pick. There are ones that go up to, I think, 350 cc, but I don't see any reason wasting money (though it's not a lot) on one that is overpowered for our needs. We just want something that will allow us to toodle around perhaps 2/3 of the island at almost the same speed as a car. I want to do as much as possible, and so I don't want to spend extra time getting to places. With the speed limits and roads, there, however, I'm not sure if there will be much difference in what I rent - but that's why I'm posting these questions!

How fast can, and do, those things go? What cc do I need? We don't plan to go anywhere exotic, but do want to go to more than just Oia. Anyone have any advice? Also, I know you don't need to buy a lot of gas on Santorini, as it's small, but what kind of gas mileage do those things get?

All in all, should I just rent a small car and be done with it? Are there any affordable convertible cars available? My husband wants to feel like he's outside. We're going early October, so I think the weather will be good - not too cool but not too hot.

I asked the car/ATV rental place a question regarding ATVs but I'm not sure they understood my question, so decided to post here. Thanks.

What atv shop are you looking at?

I'm not glued to any company yet but lots of people recommend Tony's: //www.santorini.com/rentals/tonys/

After looking at this site, I realize what we may have driven back when we were in Santorini (but didn't rent from Tony's) may have been a quad bike, not a three-wheeler. In any case, I'm sure you know what I mean, and the link above will take you to a picture that shows a number of them. Which would you choose, if any?

A couple follow-up questions:

Do they all take 2 people, even if it's not the most comfortable ride?

Do you need an international driver's license for one of these? We got one before, but at that point we were planning to get a car instead.

I've been looking up motor inn, it shows photos and prices along with amount of passengers. Waiting for reply about international license .

I've been looking up motor inn, it shows photos and prices along with amount of passengers. Waiting for reply about international license .

Hi - Just curious if you had heard anything. Also, what is "motor inn"?