which year Prius has the best gas mileage?

why don't you get a car that isn't a POS? Toyota is lame dude, and besides that, they aren't as reliable as everyone makes them out to be. If you want a Japanese car get a honda, or better yet, get a subaru. Also, sidenote: Why do you want a hybrid? You still burn gas (although not as often) it still makes the same emissions as every other car... your better off getting a diesel engine. Those easily hit the 50 mpg mark since a gallon of diesel fuel has about 2x the amount of energy that a gallon of gasoline does. Burns cleaner to nowadays

The 2004-2009 gets about 15% better mpg than the 2001-2003.

The 2010+ is supposed to get about 15% better than the 2004-2009.

However, what you actually get depends upon a number of factors. In particular, with the 2010+, the engine size was increased to get better highway mpg at the expense of some city mpg.

My 2004 Prius MPG from the logbook. (Complete years only):

2003-2004 -- 50.8 mpg 17,628 miles

2005 -- 52.6 mpg 14,688 miles

2006 -- 56.3 mpg 16174 miles

2007 -- 57.3 mpg 18384 miles

2008 -- 59.9 mpg 21755 miles

2009 -- 61.4 mpg 16177 miles

2010 -- 65.2 mpg 12134 miles

2011 -- coming soon

As for the troll. My 2004 Prius has cost 12 cents per mile for dealer maintenance, tires, and fuel combined over the 125,000 trouble-free miles I've driven it so far, according to the logbook I keep. It still runs like new. So does the 2001 that my wife drives--though she doesn't keep a logbook. Based on the high owner satisfaction ratings, my good experiences are not unique. Many Yahoo Prius group members have purchased a second or even third Prius. You don't do this if you have had a bad experience.

http://www.ctvbc.ctv.ca/servlet/an/local/CTVNews/2...

The battery is a non-issue. It rarely fails, particularly in the 2004+ models which have the improved battery, and the cost isn't all that much--under $2000 for a new one, $1600 for reconditioned, or $500 for one out of a wreck. Installation is about $500. This is similar to a transmission replacement in an old fashioned car.

http://www.trademotion.com/partlocator/index.cfm?a...

http://www.re-involt.com/

All the Prius since 2004 have had essentially the same fuel economy. We have two of the 2002 Prius in the family, and they are noticeably less efficient than the second and third generations (2004+). We get 45 mpg average in mostly city driving but some long trips, while I don't know anybody with a second or third generation who gets below 50 mpg.

Reliability is another issue. Our first generations have a lot of trouble spots while the second generation has only one - the inverter coolant pump. Repair for that runs around $500 parts and labor but the replacement is the improved design... so far, so good, as near as I can tell. Some of the first generation hybrid batteries have also failed, as many as 2% of them after 10 years according to the first source. The batteries were improved for the second generation and hybrid battery replacement is something only uninformed people worry about. Hybrid battery replacement with a new design pack is a little under $2500 parts and labor, so if my first gens ever need it I will buy the $1700 pack and do the job myself. I don't know where the story of it not having the battery management of the later models came from - the management has not changed visibly since the first ones. It is not possible to run the hybrid battery to zero by driving any Prius. That said, the 12 volt auxiliary battery is a weak spot in all model years and lots of people replace it with an AGM battery for about $200. Some of the early ones were AGMs and some were flooded cells (based on reports from people who shone light through the cases). I don't know about later ones but it sounds like most or all of them are flooded cells (based on the reported failure behavior).

For all that, any year Prius is supremely reliable. Mine has over 150K miles and has had no repairs except for broken windshields and worn out tires and wiper blades. The brakes still look like new. My wife's is closer to 110K miles but has the same service record. Nowhere near as reliable as the 2004+ model years they are still by far the most reliable cars we have had in 40 years.

The third generation (2010+) has the highest fuel economy estimates. It's easy to get great mileage with a 2nd generation as well (2004-2009). The first generation (sedan) had the lowest fuel mileage estimates.

It has a lot to do with how/where you drive. I drive a 2nd generation Pri and exceed the mileage estimates of the 3rd generation. I get low 60's in the summer and mid-to-high 50's in the winter.

For the 2nd generation, the non-touring models (with 15" wheels) get slightly better fuel economy than the touring models (with 16" wheels).

The current generation Prius gets the most MPG. 51/48

Most people are getting above the EPA

1st Gen Prius

depends if you include the $4-7000 cost of a replacement battery as the earliest models are starting to fail, the earlier models didn't have computer controlled charging so if you ran the battery down to zero more than a few times you could wreck it, so only the later ones are worth looking at

That is interesting