Gen III FE By Year on Fuelly

That is the case with any car.

 

And you numbers posted above, MPG is going up, not down.

 

The way you worded the question, "

Does this mean the mileage gets worse as it ages??!!" lead me to believe you were asking if a car's MPG drops as IT ages, not as the new model year comes out.​

 

Johnny Zero, please explain your numbers. It appears that the numbers are trending up. But I dont know what your numbers represent.

 

In my case, I lost interest in getting the highest fuel economy I could after the first year (before that to tell the truth). I get in the mid 40s in local short trip driving and low to mid 50s on the highway without trying. For me there is no incentive to milk that last few miles a out of each gallon when I get the level of fuel economy without trying.

Earlier adapters (Gen 2 and Gen 3) are more likely to be hardcore fuel economy aficionados instead of someone just looking for an economical practical car. I think the early adapters are more likely to keep up their high fuel econony ways then later buyers.

 

You sorta have to leave out the 2012s because most owners have not gone through a full year season cycle. Winter is going to clobber the mpg of 90% of the 2012 owners.

 

No. Not in three years. 2012 cars haven't gone through winter driving . The 3rd gen Prius gets about 20% better MPG in the Spring-Summer than in the Late Fall-Winter. In addition, 2011 Prius has experienced a relatively mild first winter compared to the 2010 Prius' first winter - so overall 2011 Prius appear to get better MPG than the 2010 Prius. If the trend towards global warming stays on course, 2012 will be a mild winter as well. If you look at my 2010 Prius mileage log under "HyperDrive One- drydem" under Fuelly.com you'll see my overall increase in fuel efficiency over time. I'd like to say its all due to additional driver skills but I know that part of it is because the winter 2011 was milder than the winter of 2010, so my 2010 Prius' 2011 winter time MPG improved signficantly over 2010. What makes my Prius's MPG drop - is speeding ... going over +60 mph - like when I went 80 mph so I could cover +800 miles/day the Prius MPG drop to 44 mpg..

Over a very long time ( 8 to 16 years), the pistons and engine block cylinders can wear down inside a gasoline engine. When the gap between the pistons and engine block cylinders increases, the max compression drops per piston-cylinder pairing which lowers the energy efficiency of the gasoline engine. Changing the oil , oil filter, and air filter at appropiate intervals mitigates this wear and tear - as well as the use of synthnetic oil.

 

Winter is going clobber the mpg of all (100%) of the 2012 Prius owners.
Even with a heated garage like Jay Leno or an Engine Block Heater - winter like driving temperature will take a bite out of the Prius' MPG.

 

I would be surprised if it was anything to do with age. More down to the inability to sustain higher mpg over long term ownership and the greater amount of people in the sample pool for older cars.

 

That hasn't been the pattern on my old cars, at least since fuel injection became the norm. They have all done better with age, even beyond 200k miles.

But it is possible that some mechanical degradation has been masked by improved tuning of the nut behind the wheel as it ages.

 

Based on what you posted, It's probably just because of the number of entries per year. 2,000 5,000 16,000.. the more people reporting, the more drivers you have to bring down the average.

That's the thing about an average, I average 55, some people average 65, and others average 42. It's the ones averaging 42 that are killing the numbers.

 

I am not sure but in your case you are getting better