Weekend highway trip Columbus OH to Buffalo - MPG report

Weekend highway trip Columbus OH to Buffalo - MPG report (Final UPDATE)

The entire family, sans dogs, are taking a trip from Columbus Ohio to Buffalo New York to visit some family. This will be the first long highway trip in the new C!

It will be interesting to see how the MPG is affected by the additional weight of 3 more passengers (adding about 450 pounds) and the hatchback storage full of luggage and a set of golf clubs (another 100 pounds).

Tire pressures are set at 42/40

First Update:

After the first part of the trip yesterday, I was very impressed with the C. The weather was sunny and temps ranged from 75-80 degrees. Some wind but it did not seem to bad. I stuck to speed limits the whole way. 65 on interstates (which was 95% of the miles). I was able to draft a couple of big rigs along the way (safely...let's not get into that debate)..but most were going slower than me so I had to pass them..I was averaging above 55 MPG until we hit I-90 in PA...the roads seemed very rough and noisy which I think caused higher rolling resistance and caused the MPG to drop a little...here are the quick stats after I stopped the car at our first waypoint. So far I think the car is amazing...EPA 46 hwy....not.

Another interesting note: I was in ECO mode the whole way with the AC on the entire time set to 74 degrees....At a later date, I plan to investigate more about the effects of AC in the C with my Scanguage....

I will update after another 300-400 miles of travel today....

Second and Final Update:

Had to come back to Columbus late on Saturday night....left around 9:00pm arrived home at 2:30am. The weather was clear and temps in the high 50's low 60's...Again..I went speed limit the entire way, 65 MPH. No air conditioning was used. This time around the mileage was less..50.9 as indicated by the trip computer. The entire trip of 700 miles netted out 52.7 MPG...which translated into 51.5 actual. Based on this trip here are a few of my conclusions/thoughts:

1.) Air temp made a difference on MPG...My trip to Buffalo was done with temps in the mid to low 80's, trip home was done with temps from high 50's to low 60's

2.) Effect of using AC on MPG in Prius C needs to be investigated further....I think the effect is less in the C due to the fact the entire system is electric....and when on the freeway the car is managing the traction battery to maintain a SOC of 60%....I also measured, via scangauge, the draw of the AC....I measured the AMP xgauge value which shows me the current draw to and from the battery.

While parked...in ECO mode

AMP Reading with no AC with radio and DRL on is 1.5-2.0 amps
AMP Reading with AC on full blast with radio and DRL ranged from 13.0- 15.0 amps
AMP Reading after cabin is cooled down with radio and DRL 6.0-9.0 amps...

While driving in EV mode vs Parked, the AC draw is about the same and when driving with ICE on....it is very hard to tell if the AC has any effect since the car manages the current flow to and from the battery so well. Maybe monitoring the instant MPG gauge at the same time would yield some more info...?

So my assumptions are: that the biggest hit using the air conditioning is when the ICE is NOT running since it will discharge the traction battery at a much greater rate....which will force the ICE to run more frequently when the battery hits 40%...thereby lowering MPG. On the highway....not much hit on MPG. To be continued...

3.) An extra 500 pounds has pro's and cons's.

Pro's

Lowered the car slightly for better aerodynamics?
More inertia...allowed for longer glides when I had the chance

Con's

More weight more power to get up to speed = Lower MPG
Grumpy teenager's in the back seats (who actaully admitted later that the seats were not bad, but it was tough to sleep back there....)
Took much longer and more friction brakes to slow the car.

That's my report and my thoughts...hope it helps give some more insight into Prius C Highway driving.

-M

 

Thanks! I just updated the first post with final observations.

-M

 

Well....I had a full car.

I am only 5'6" my wife and daughter are 5'1" and my son is 5'9"....
Me, My wife, and two teenage kids...Wife and I thought the seats in the PC3 were very comfortable for a 5 hour trip...Kids thought they were comfy in the back, but were not comfortable trying to sleep. Leg room for the kids was adequate. My back was fine throughout the trip...I did miss the adjustable lumbar I had in my Infiniti....

Hope that helps..

-M

 

Another trip back to Buffalo this weekend! Just for my wife and daughter. My wife did a great job and really got great MPG...She set the cruise for 67 and this was the result on the first part of the trip. I will update on Sunday for overall trip mileage! I am very happy to see that the car is getting much better hwy mpg than EPA....

-M



UPDATE:

Here are the final trip Stats for this past weekends trip......I love this car!!!