[First post, so bear with me.] Until this morning, I had a 2010 Prius Two which I've driven 145K miles (and loved). Over that time, the displayed MPG was typically in the 48-51 MPG range. I went to buy a used 2012 Prius Four this afternoon (with 31K miles) and was ready to sign on the dotted line, but noticed that the Trip A (with 600 miles) had a reported MPG of 38! I'm not an expert (nor a hypermiler), but I've never seen a displayed MPG that low on my Prius (when averaged over say at least 50 miles). The car (clean CarFax) is at a dealer so I don't know how it was driven previously. Should I run away from this car (because 38 indicates something is seriously wrong somewhere) or buy it (because the price is right) and there is some logical explanation for the low MPG (only driven to church a mile away on Sundays)? As a somewhat-scientific test, I reset the trip, drove 5.6 miles in the car (42MPG), then went next door and test drove a 2015 Prius Three the same route (39MPG). Both cars were cold, the 2015 brand new (1 mile on the odometer and colder than the 2012). Generally I'd say those two MPGs were comparable (given the traffic conditions, short distance and 40 degree weather), so that makes me think the car is okay. Was there a software change between 2010 and 2012 model years that would explain this difference? Puzzled in NJ.
Other drivers, other conditions, and repeated short trips (especially on a used car lot) could give it a low trip mpg. I'd ignore that, and use your personal results as a better guide. Can you check the tire make & model (are they non-original, not low rolling resistance) and if they are underinflated?
Sorry but test drives are a poor diagnostic unless you have enough time, an hour, to handle warm-up and a well planned benchmark route. For example, I bought a used, 2003 Prius in Fort Worth and drove it nearly three hours, 'Texas I-20 style', to Shreveport LA . . . 39 MPG, not the 52/45 City/Hwy MPG! I briefly thought about turning around and taking it back. But I asked myself, 'How can a government bureaucrat get better than 39 MPG?' So the next segment, I used cruise control at 60 mph and got 53 MPG. It was 800 miles back to Huntsville and I found there was a 'knee in the curve' at 65 mph, 52 MPG versus 70 mph, 49 MPG and 75 mph, 39 MPG. Still, you need to be happy and buying a car is a significant expense. I was tempted to return the car but instead used the initial, low MPG as a challenge and eventually mastered the car. GOOD LUCK! Bob Wilson
My guess would be you don't have a problem here. I mean I wouldn't trust a MPG reading that I hadn't read or set myself. But my concern is that you are already concerned. And I suppose it is possible the vehicle could have issues that are affecting it's MPG. The dealership should WANT to sell you the new/used vehicle. I'd ask them if you could take it for a significant test drive. Seriously, like an hour or two on the highway, or maybe even if you could "rent" it for a day or two. If they will let you rent it..rent it for a week and see how the gas mileage responds. It's a used vehicle with 31,000 miles on it...you putting an additional 50 or more on it, shouldn't matter. Then you could see before signing on the dotted line if the MPG is a problem or not. If you aren't comfortable with it before you've bought it, then you are getting off to a bad start with a new to you vehicle. And since you have owned a Prius before, I think concerns about MPG valid. Once you sign on the dotted line...the vehicles yours. Even though my guess is that the chances are rare, Yes, I'd rather establish whether there is a problem before I bought the vehicle.
Thanks for all of the advice. I ended up buying the car, and on the ride home achieved 53 MPG, so I think my MPG concerns were unfounded (though I'm still curious how you drive 600 miles and get only 38MPG). By the time I saw the tires, they were properly inflated by the dealer, and there didn't appear to be tread wear indicative of under-inflated tires, but I don't know for sure.
my guess would be that on top of the 600 miles they turned the car on at the dealer's lot a LOT (if nothing else to check it charge the battery ) and/or moved the car a few dozen times going a mile or less a time ... that kills the MPG in a hurry...
