MPG changes to much better on hyw.

Did you previously was the engine under cover missing ?

 

The reality for me has been that while The Prius city gas mileage is impressive, I get better gas mileage on long highway road trips.

I don't know how the EPA test formulates their city estimates. But for me? While city driving can produce phenomenal MPG, if the engine is warmed up and the battery charged, often the Stop and Start nature of a lot of city driving results in the engine cooling down and then once restarted having to warm back up and that just naturally results in lower MPG's overall.

So even though Toyota parades the higher City MPG numbers, my driving experience still has highway driving getting superior numbers.

I'm not unhappy about this, as the real deal maker is what you are getting tank to tank and as a combined number.

 

My wife drives our Prius as her daily commuter. Her daily commute is maybe 40% city / 60% hwy, so we do not track each individually. We watch it more on a tank-to-tank basis. When we have done long-distance road trips that were all freeway [70 - 80 mph] it has generally gotten better mileage for us.

Winter driving sees a big drop in mileage. We see a lot of single-digit positive F hi temps and double-digit negative F lo temps. The software has the ICE running a lot more for the purpose of making heat to keep the system warm. That is where the inefficiency goes in winter driving. Along with whether or not you are spinning your tires a lot on ice, and pushing through slush piles.

I suspect that the under-cover helps to hold in a bit of warmth for the ICE. Without those covers, more slush is tossed up, so the software has the ICE running more to compensate.

 

Maybe you're just trying harder too, on the highway. And/or dropping your highway speed a bit? The latter really helps. Also, I've found the cruise control on the Prius pretty good at maintaining speed with minimum expenditure of energy, watching my ScanGauge.

I think the official mpg ratings, with better city numbers, are pretty much accurate. The car really does shine in low speed city driving, if you work at it.

 

Yes the plastic covers should help. I remember many years ago reading article on improving aerodynamics of SUV/trucks, and this was the area they stressed the most. Something like 20-50% of drag coming from undercarriage.

But most likely it is a combination of several factors: warmer temps, better fresh oil, you getting used to driving Prius efficiently.

 

Same here, plus my "city" driving is rarely the below 25mph, lights-stop-and-go of an actual city. Rural living ftw!

I get my best MPG on long drives with steady 35-50 MPH speed limits. I've seen 60+ going the back way from here to southern Maine.

Highways here are pretty hilly so it's hit or miss depending on which way you are going and where.

Ultimately, winter's combo of heavy, high friction snow tires + lots more engine running for warmth = low 40's mpg for me. I see high 40's all summer with the very occasional 50+ under ideal conditions.

Beats the heck out of my 16mpg 4Runner though I love that truck for around town stuff but when we travel any distance (and don't need to haul a bunch of stuff) we take the Prius.

 

I got my first 600+ tank with 70% city and 30% open road. I always do better in town. Hal

 

Maybe the covers affect the aerodynamics at high speed?

Phil