From what I remember the Full Size was the larger of the two. Usually it is a V6 or larger engine full sized sedan.

Standard was usually 4 cyclinder and just over the size of a compact, I think.

You can go to the websites for Avis or Hertz or Budget or whatever and see what venue of cars (GM, Dodge/Chrysler, Fords etc.) that they usually carry and you'll get a good idea of what I explained above.

You do know that if you bid and win, you can be upgraded at the point of getting the automobile. They will probably offer you an upgrade (if you don't like that size trunk etc.) for $7 or $10 a day more or something. So it isn't written in stone.

When we did a Priceline rental in Lake Tahoe, Avis won, and they offered us a 4 wheel drive Jeep upgrade because it was snowing, for just a couple of dollars more a day-but you had all kinds of choices in the Chrysler/Dodge/Jeep line.

The difference between a Jetta and a Passat.

Just be clear, the automobile you decide upon isn't written in stone, but the Price IS. You couldn't change venues, for example.

The one thing I try to find out with this using Hotwire or Priceline, is if the vendors that could win are IN the airport.

You don't want to win a bid for a vendor that needs a 5 mile shuttle in between. That can happen, so read all the choices clearly and find out where they are located if you are picking an exact vendor.

Fuel costs is making full size cars less attractive.

I was looking at rental car today, and on Dollar's own website, they have a category called "Lock Low and Go" which is a guaranteed "intermediate or larger" vehicle, and it's by definition cheaper than an intermediate car. Their corporate sister Thrifty has something similar called "Wild Car".

The key is that they'll give you whatever intermediate or larger car they want to, and you don't get to choose.

For my rental, I'd rather give $1 more a day to get an intermediate car. For driving say 100 miles, you can be talking about a difference of 3.3 gallons of gas ($12) with an intermediate vs 5 gallons of gas ($18) with a full-sized car or a medium-sized SUV.

I don't need all that extra size. So, no thanks. I'll pay $1 more for the intermediate.

The confusion for me is that Hotwire's catagories go like this:

Economy 16.95
Compact 17.95
Mid-size 18.95
Full-size 18.95
Standard 19.95
Premium 30.95
Luxury 40.05

The Standard is actually slightly smaller than the Full-size, yet it's MORE expensive.

The only thing I can figure out is that, as a previous poster suggested, it's related to gas prices.

Maybe no one is renting full size anymore due to gas mileage??

It's related to gas prices.

On several rentals recently instead of gettinga compact that was booked I've been given a lot bigger cars, some were SUVs.

And if you buy new cars and trucks too, right now- they are practically giving away the work trucks and large sized V8, low gas mileage vehicles. I'm not kidding.

And that oftentimes has much less correlation to SUV's which are of very differing gas usages, IMHO.

Yes, that is the reason the standard's are often MORE $$ than a full sized sedan.

It could be something like this:

Sub-Compact: Chevy Geo size
Compact: Ford Focus
Mid-Size: Ford Fusion
Standard Size: Ford Taurus
Full Size: Ford Crown Vic