24 mpg consistently in town - why? Baffled.

correct. you need to measure average mpg's at the pump. nothing else is close to accurate.

short trips around town are mpg killers. warm the car up before giving a test drive, take the prospective buyer on a varied route under all conditions, and you'll see a nice average mpg number.
that's how prius work.
plus, in this market? you're gonna make a fortune.

 

A 2014 is 3rd Generation but 24mpg seems pretty low. I wonder, are these very short drives on cold days? If you're only going a few miles in the cold the gas engine is probably running the whole time. Once the engine is warmed up you'll see better mileage, that's why you see 45mpg on the highway (which is pretty good for highway driving in winter tbh)

 

Bisco and Malachy nailed it. If you are making short trips and running with the AC or defroster on the car never has a chance to get into hybrid mode. To maximize mileage shown in the history (on the dash???) , turn off the heater and drive more than just the 5 minutes to the corner store. Take the long way home and let the engine warm up all the way.

Back in the old days there was one other mileage killer. Occasionally the tech would over fill the engine during an oil change. Too much oil can cause the oil to rise too high and the crankshaft would churn it, causing a lot of lost horsepower.

 

the only way I could get close to 30 mpg was pulling a trailer of dirt bikes at 80mph and running the HVAC all night while camping the weekend....

check your tire pressure and get a couple 30-40 mile trips on it. if you're burning a lot of oil your cats may be clogged also.

 

?

 

I'd recommend you get the Hybrid Assistant app for a cell phone and a recommended ODB2 bluetooth adapter Hybrid Assistant: OBD

It should help figure out why by choosing the reporter option after you have driven the car with the app on your phone connected to the ODB2 adapter in the OBD2 port in the Prius.

 

The sea level change should not be an issue. I go from Sea level to 6,000 feet and back monthly.

I was reminded this evening that sometimes a dragging brake caliper can cause poor mileage. It's worth putting on a rack and give them a spin.

 

anything related to the car would effect city and highway mpg

 

This is the results of short tips in an ICE vehicle.

9 yrs=3285 days divided into 48,000 miles=14.6 miles/day. Very few of these trips ever reached proper warm up temps nor for long enough distances to negate the warm up penalty. The best way to solve this is with a plug-in that can cover those distances.

Short trips are also hard on the HV pack. You also may have a tired traction battery that's not assisting as much now. Hwy driving doesn't stress the battery very much so mpg's aren't as affectd.

 

Not officially, but the OD is very close to 195/65R15, the stock 15" size. The official 17" size is 215/45R17, which actually a bit smaller OD the 15" size.

You might try the rear wheel spin test, per "3rd Gen Rear Brake Drag Info" link in my signature.

 

Yes, that's what I was talking about.

As for the tires... you should have low rolling resistance (LRR) tires on the car. They have a design that produce less friction when they flex, and therefor waste less energy.

 

One thing though: there's a LOT of tires making Low Rolling Resistance claims,, that in actuality have little benefit. There's also some tires that don't make LRR claims, but do pretty good.

We changed our 17's from well-worn Michelin Pilot HX MXM4, to Michelin Primacy MXM4, both being 2115/65R17. Both had the Michelin LRR logo "Green-X", signifying LRR. New tires can traditionally drop your mpg some, but in this case it was a nose-dive, about 20% drop, for the first few tanks. Very gradually came back.

 

OK, I’m no expert on Prius history by a long shot but I thought the Gen4 started in 2016. However, if your’s is truly a gen4, you can address your concerns as far explaining it by pushing the Trip button on your steering wheel to display the ODM with the accumulated mpg, and then hold the Trip button down for a few seconds to reset the mpg. Or at least that is what I’m told.