Incredible Yaris Hybrid city fuel economy

The most I've gotten was like 84mpg with 4 people in the car.

I can believe it if they drove like complete assholes and the course was mostly downhill/flat.

 

You have to remember that the C will cruise at 99.9mpg (so who knows how high it's actually getting) on the ICE if you're doing 35-40mph on dead flat ground. If their trip consisted of mostly this low speed driving with very few stops, I can see 100+mpg.

 

Doubt it's even remotely close to what we consider city driving! Long stretches of flat, rural roads with little traffic so you can hypermile to your heart's content!

 

data provided:

2012 Prius c ( mpg rating = 3.8 Liters/100km, 50 mpg combined)
reported mpg for this route = 1.68 liter/100 km (140 US MPG)
130 km distance (80.8 miles, Univ of Pretoria aka Tukkies @ 1350 m altitude to hartbeesportdam @ 304 m altitude)
1:40 hour trip.
elevation change 1000 meters ( 3281 feet) drop
average speed 78 kph = 48 mph (130 km/1:40 hours)

analysis:

Hypermiler Wayne Gerdes drove a Prius C on the Californial superhighway at about 55 mph and achieved 80 mpg with a pre warmed up engine using mainly DWL with regularly inflated tires but that a far cry from 140 mpg. So how did the World of Wheels do this stunt? Gravity. The elevation change from their starting point at the University of Pretoria (tukkies) and Hartbeesportdam, South Africa is about 1000 meters drop! Note also that their 130 km trip in 1 hour in 40 minutes makes their average speed at about 48 mph which is way too fast for 130 km trip of all urban city driving - city limit top speeds are between 30 mph to 15 mph - add in stop lights and stopping for pedestrians and city speed average is likely to be about 15 to 20 mph. Their 130 km trip 48 mph average speed suggest that this route's top speed is more likely to be +55 mph at time unless they designed a route to nonstop. This World of Wheels route is likely a mix of city-suburb-superhighway driving.

conclusion:

140 mpg is possible going downhill but the Prius c's mpg going back uphill +3280 feet will not look as great.

 

Walter pretty much summed it up. Gravity makes a HUGE difference. I have a little over 1,100 ft. elevation drop on my commute home and with good weather and a sustained speed of 60mph (sometimes 55mph when traffic builds up) I have gotten as high as 90mpg over 48miles. Give me a couple thousand feet of extra kinetic energy and slower speeds and I'll get well over 100mpg.

 

Just a small correction. The altitude of the Hartebeespoortdam is at 1164 mASL and not 304 mASL according to Weather Hartbeespoortdam - meteoblue. Actually they went to the cableway station which is located around 1300 mASL. Tukkies is located at 1348 mASL. This gives a drop of around 50 meter (. I think over a distance of 130 km this kind of downhill might not have a big influence on the fuel consumption.
Other articles available at Ride & Drive - Lifestyle of cars, Dawning of a new age - New Models | looklocal Benoni and HSD for Toyota Yaris | DieselDrive Magazine give different fuel consumption figures which to me sound also very low. I am going to book a test drive with our local Toyota dealer and who knows, maybe... I will also end up with one?

 

the author Edwin Naidu in
Ride & Drive - Lifestyle of cars
say he only got 3.79 liters/100 km ( 62 mpg ) on his 130 km run...which is very beliveable.

Naidu says...
"The (Hybrid) Yaris is a funky little number with plenty of appeal. On our drive from the University of Pretoria to the Cableway at Hartbeespoort Dam, via Magaliesburg on Tuesday, it showed it is a runner if driven frugally. My drive partner Gerrie Smith and I finished second in the frugality stakes with a miserly 3.79 per 100 kilometres in terms of performance. Our challenge was to ensure a good balance between petrol and electric mode."

Gerhard Horn in
Dawning of a new age - New Models | looklocal Benoni
claims to 1.75 litres/100 Km for the 130 km fuel efficiency marathlon from Snor city to Hartbeesport. but Horn's account doesn't ring true...

Horn says...
"As part of the launch of the HSD, we were challenged to do an economy run from Snor City to Hartbeespoort to see if we could match the claimed 3.8 litres/100km....The route included both city and open road driving and spanned around 130km. It must be said that we did a proper economy run, which meant no air-conditioning, closed windows and sticking to the speed limit at all times. You may not believe this (I certainly wouldn’t have if it wasn’t confirmed by an economy run expert), but we were able to beat that figure. At the end of our 130km route, our vehicle was averaging 1.75 litres/100km."

Horn's account sounds backward because from Snor City, SA to Hartbeespoort would be a uphill climb which would have zapped the Prius c's fuel efficiency! Horn's result would be more believable if he had said his 130 km route was from Hartbeesport to Snor City...

The OP article which boast of 140 mpg said that the 130 km route ends at Hartbeespoort Dam which is different from Hartbeesport the township where the Cableway is. However, elevations can be tricky thing so - your comment does warrant double checking ... - One
can't be tooo careful.. Unfortunately, I was not able to get tukkies elevation on meteoblue so I decide to find another elevation search engine. The elevation I used previously for Hartbeespoort Dam was from a hang glider website - way too limiting. I need a search engine for elevation that found both tukkies and Hartsbeesport cover a wide region with a wide variation in elevation. There is not enough information on the OP story to determine the exact locations being used and the other accounts don't match up rightly. I can't find any World of Wheels website - Steve Mearns has his own website/mag but I found no information on this fuel efficiency rally on his website or on his downloadable magazine. I think your link to Edwin Naidu's account sounds more real and likely is the most accurate but also he is saying his results were less stellar...

The University of Pretoria (aka Tukkies) has several campus sites (locations) - I decide to use the main campus (option#1)...

1. Hatfield Campus <- pick this one...
2. Groenkloof Campus
3. Mamelodi Campus
4. Prinshof Campus
5. Onderstepoort Campus
6. Sandton Campus
7. Hammeanskrall Campus

The official address is
Lynnwood Road, Hatfield, Pretoria South Africa

To find the elevation for both locations I use..
Elevation map, latitude/longitude of your city or address - veloroutes.org

For: Tukkies (Lynnwood Road, Hatfield, Pretoria South Africa)
The latitude for this location is: -25.7612199
The longitude for this location is: 28.2494170
Elevation is 4546 feet

For: Hartbeespoort Dam ( the OP story)
(Hartbeespoort, Bojanala, North West 0216, South Africa )
The latitude for this location is: -25.7910377
The longitude for this location is: 27.8663075
Elevation is 4014 feet

Change in elevation is - 532 feet ( - 162 meters)


For: Hartebeespoort Dam Cableway, Johannesburg
(The alternative account address = R511, Johannesburg 1665 )
The latitude for this location is: -25.9581608
The longitude for this location is: 28.0178850
elevation =4470 feet

Change in elevation of - 76 feet


For: Snor City, SA
The latitude for this location is: 9.2922613
The longitude for this location is: 123.3029893
the elevation is 32 feet

The uphill change in elevation from Snor City to Hartbeespoort 3982 feet!

Just dropping from 500 feet elevation to 300 feet elevation gives me a 10 mpg boast.. I'm not sure what another 300 feet drop would do.... This story gets more confusing the more i delve into it I think the reader should be skeptical wrt to this story -- something is amiss...

hope this helps
Walter Lee

 

If you find the route using Google Earth, you can display the elevation profile. The route from Uni of Pretoria to Hartbeespoort dam seems to have gentle slopes of about 2% grades and no flat sections. I couldn't find Snor City. Google Earth doesn't let you adjust the route, so the directions it picks are what you get.

UPDATE: I'm talking about Google Earth desktop. There are two ways to display the route profile:

1. Right-click on the route on the map. The context menu should include "Show Elevation Profile".
2. There is also "Show Elevation Profile" under the Edit menu, but I can't quite work out how to enable it. I thought that selecting the text of the directions enabled it, but that stopped working.

Note: The elevation profile calculation will depend on the size of the window you display. The shape will be the same, but the values might be different. A bigger windows allows more slices so the numbers tend to be bigger. Maintain the same screen ratio to compare. Examples:

• At 1000 pixels (approx.) the route has an Elevation Gain/Loss of 322m / -520m and a maximum slope of 6.4%, -6.2%
• At 1900 pixels (approx) the route has an Elevation Gain/Loss of 359m / -557m and a maximum slope of 9.0%, -6.9%

It would be nice to be able to choose a slice size or smoothing for consistency, but I haven't found that yet.

 

"Snor City" is a nickname for Pretoria and means "Moustache City" since most of the manly men living there have moustaches. Tukkies is the nickname for the University of Pretoria formerly known as the Transvaal Universiy College (TUC ) or Transvaalse Universiteit Kollege (TUK) in Afrikaans.

 

Hi Braddles, which of the Google Earth options do you use? Desktop, Web or Mobile?

 

The starting and ending street addresses of this SA fuel efficiency rally would have made this easier to validate. Regardless of what experts are reportedly overseeing their fuel efficiency rally - to duplicate and validate their fuel efficiency result - a full disclosure of which roads were driven and in what direction and during what times is necessary. Any thing less is no more than a circus show. Precise tools like Google earth need reliable and precise data to input enter - which sofar has not be provided.

 

I fully agree walter Lee, and in the long run services like Fuelly will paint the full real world picture like it does for the other Prius family members. Have a look at Toyota Prius C MPG Reports | Fuelly for the picture so far. At Toyota Prius MPG Reports | Fuelly the statistics for the GenI, GenII and GenIII Prii are given. To see the statsistics for any given year you can add a forward slash and the year to the end of the URL e.g. /2007. The statistics for the plug-in Prius is given at Toyota Prius Plug-in MPG Reports | Fuelly.
Personally I prefer the real world figures that those obtained from some experiment that does not reflect the true picture.

 

You know that saying... YMMV... it is so true.

I agree that the stats on fuelly.com are going to be more appropiate to the majority of Priuschat.com readers because the fuelly stats are by USA drivers - South Africa is a totally different driving environment. My guess is that SA drivers maybe able to do things I (as a USA driver) can't do. One thing I'd like to point out is that South Africa also has fewer cars per capita than the USA (USA has 808 vehicles per 1000 people while SA has 162 vehicles per 1000 people) AND SA uses less crude oil than the USA ( USA 19180 thousand barrels per day in 2010, SA 553 thousand barrels per day in 2010) which means SA is not going to have as many traffic jam as the USA - something I have to deal with almost on almost a daily basis. Less traffic means a driver can take hypermiling to its truest limits.

 

btw: If the known 130 km route was truly an all city route and it had speed limit of 50 kph (31 mph) and the driver completed this route in 1.66 hours - the Mean Value Theorem (this is basic calculus stuff) says that at some point in that trip the driver was speeding over 78 kph ( that might equate to an automatic speeding citation in some jurisdictions)

 

I'd love to try hypermiling a c for a week or two.

 

well obviously you cant get that by just driving around in any case, but still, nice.

 

Without desktop Google Earth you can use HeyWhatsThat Path Profiler, which uses Google Maps. Select start and end points, hit Smooth Route and then hit Draw Profile. Sometimes it doesn't work because the smoothing generates a 0 length section.

 

Agree. All of these ultra high MPG numbers require driving like a buffoon, at the very least.