30% under mpg rating, any tips?

In spirit F8L. I am on the other coast so I keep looking for GWmort in his Volt when I go thru Delaware. No sitings yet.

 

Another tip for getting good a "trip MPG" for R-P. Always start your journey from the top of the tallest dyke you can find.

Sorry if that joke was in bad taste.

 

Drive like normal But
No harsh acceleration
And keep momentum

 

Good luck....I live in DE and have only seen a volt on the roads one time - not counting when GW and I met up so I could check out his Volt.

I've seen a Prius v already on the roads, and that's not counting the guy I know that owns one.

 

Good luck. He never drives the car beyond 20miles so he won't have to use any gas.

 

Ok I didn't know you had such high speed limits. Most of our roads are 110 km/hr max (and many only 100 km/hr).

The speed really makes a big difference. Your figures don't look too surprising. Lets look at the maths. The energy (per unit distance) to overcome wind resistance is proportional to the square of the speed, and typically the wind resistance starts to dominate over rolling resistance at about 40MPH.

So at 62 MPH the energy (per unit distance) needed at the wheels is approx :
E1 = 1 + (62/40)^2 (in arbitrary units)

At 75 MPH this energy increases to (in same arbitrary units)
E2 = 1 + (75/40)^2

It is easy to verify that the ratio E2/E1 is approximately 1.3. So we would expect the fuel consumption at 75MPH to be about 1.3 times a high as that at 62MPH. This is almost exactly what your results indicate, 47/1.3=36.

She should be able to get 50+ MPG under those conditions, unless there are lots of traffic jams or something. I often get about 4.0 l/100k (59 MPG) under that type of driving conditions. Try taking the Prius around some of those low speed routes yourself and see what you can get. Try to practice a little bit of "pulse and glide", especially when the speeds are under 66 km/hr. Try to do some longer glides in sections where the traffic is slowing (eg approaching an intersection) or on sections of road where the gradient is even very slightly downhill. You initiate the "glide" by momentarily removing your foot from the accelerator pedal (should cause the engine to cut out and instantaneous L/100km to go to zero) and then immediately re-apply very light pressure to the accelerator while keeping the engine off. (You may have to wait for warmer weather to get this really working well though, if you need lots of cabin heat).

 

...for EU that Toyota obviously needs to report comparative MPG at 120 miles per hour <lol>. It will be lousy MPG but I am not sure other cars are better MPG at high speed? Several Prius drivers in the states have been arrested for going 105 Miles per hour, so we can get that fast anyway.

 

I have found over long distances that I get the best fuel economy whilst driving with cruise control on as I am less tempted to accelerate rapidly, decreasing my MPG.

 

I have to say that I am getting very low mileage myself... Yes, it is winter here in Maryland, but I'm seeing my actual fuel economy going to between 30mpg to 37mpg..!!! I put a fuel system cleaner in my tank after my last oil change and I was getting consistently 37mpg, but after that tank, it started decreasing. I'm starting to think something may be clogged in the injectors or possibly the fuel filter. I don't know what to think... I don't "drive it like I stole it" and do a mix of highway and city driving. I know that 87 octane is a dirtier and less refined fuel so I'm thinking that's one of the reasons for a possible clog somewhere. Anyone have any ideas here..? Btw it has almost 70,000 miles on a 2008. Thank you!

 

What sort of driving do you do? What are your tire pressures? What else has changed?

Tom

 

I bought a second hand Prius 2007 about a month ago, with 44.400 km on.
I live in Macedonia, Europe, where winters are very cold (up to -20ºC) and summers are very warm (up to +50ºC). I put only about 500 km so far, but it is enough to get to know the car a bit.
When I first got the car, I took a 300 km trip right away, 2x150 km. (160 km of highway and 140 km open road with long uphills, at a temperature of -6 to -2 ºC. Speeds from 90 - 130 km/h on the highway, 50-70 km/h uphill-downhill, 70-100 km/h on a flat open road). The result was 4.9 l/100km according to the monitor. Since then I reset the meter and I put only 200 km so far, all city driving. I got REALLY disapointed from the mileage in the first 100 km - huge 9.4 l/100km according to board computer! I was sure that something was wrong with the car. Anyway, I urged myself to understand that in that period the temperature was in the range from -20ºC to max. -4ºC, there was plenty of snow, and my commute was really short - 6km from home to work, then the car stayed outside for 8-9 hours, then 6 km back home. The other commutes I made were even shorter - up to 5km. Meanwhile the weather got warmer (arround zero ºC). I got another 100 km without previously resetting the meter. The milleage raised from 9.4 to 7.6 l/100km. By using simple math, I calculated that if in the first 100 km I got 9.4, in the next 100 km the car consumed only about 6l to make an average 7.6 l/100 km. That is suprisingly good, having in mind that it is still cold (as I said, arround 0ºC), and I have winter tyres on - Hankook W44, nothing special). Just for comparison, meanwhile at work I drive in the city a Seat Ibiza 1.4 TDI, a Seat Leon 1.9 JTD and a Peugeot 206 HDI (all diesels and all praised for their fuel economy). I reset the meters in every one of them. The Ibiza has the best average - 6.8 l/100 km, while the Prius, as I said before, got arround 6l/100km. A friend of mine has Mazda 6 2.0 diesel. When the temperatures were -20ºC to max. -4ºC, he got above 10l/100km!
My point is - 37-38 MPG is EXCELENT result in cold winters, for any car, and for short commutes. Anybody who claims that gets more, probably has longer commutes. I think you will get 4 - 5 l/100km city in the summer, and the diesels I mentioned before will get 6/l/100km.
In the cold winters Prius needs more time to warm up and to actually become a hybrid (2-3 times longer then a diesel) but afterwards it compensates a lot more with the battery. So, for the next winter I will definitely block the grills to shorten the warm up process.
Furthermore. From all the research that I have done so far, it is ESSENTIAL to learn how to drive the hybrid to get good mpg. In fact, it is important not to accelerate briskly, but it is far more important to anticipate stops and drive like you dont have brakes. Even if you have to accelerate briskly, take your foot off the gas afterwards, and then press just a bit again to glide. When you then anticipate a stop, take the foot off the gas completely to coast (green arrows on screen) and crawl that way to full stop. Not only that you save fuel, but you also save the breaks. It is also important to use the EV button when you see a situation when you know you gonna have to drive slow. Pulse and glide is a bit tricky, but you can quickly get used to it. It helps a lot, there are sections up to 600m that I pass without arrows on the board (free ride).
So, I have seen that in order to get good mpg, it is not enough just to have the Prius. You need regular maintenence, regular checking the tire pressure and air filter, regular battery checks (it it is weak, the engine will turn on often to charge it), obtaining some driving skills, and normal weather (with temperature above freezing).
Another thing... According to my calculations, with a little caution with the Prius you can save at least of 2L/100km (combined) compared to other midle sized cars. If you pass 200.000 km, which is normal, you will save more then 5.000 eur on fuel (with the current prices). If everything is OK with the mashine, you can save additional 1.000 EUR on maintenence, compared to other non-hybrid cars of the same class (both diesel and petrol).
I got my second hand prius for 10.000 eur.... so, I aks myself the question - can I have a quality middle-high class comfortable and quiet car with automatic transmission, full-packed with accessories, for 4.000 eur (10.000 which I gave minus 6.000 which I will save, if hopefully everything is OK)? I dont think so.

 

By gum, I enjoy reading through threads like this one!

New Prius owners come on with mileage concerns who state their case
simply, reasonably, without crying like a baby, screaming bloody
murder, or looking to find a scapegoat for a lack of research before
buying their car.
It's both refreshing and reassuring. :rockon:

That said, getting very good FE takes a little effort, and an
understanding of what conditions are going to kill MPGs in the cold
months, no matter how hard you try.

As has been mentioned, there are numerous "usual suspects" for lowered MPGs.
These would include:
* Tire/tyre type - LRR preferred, 5K mi break-in period
* Tire/tyre pressure - 40/38 psi front/rear, but not above max sidewall pressure
* driving at speeds in excess of 65 MPH
* 12V battery condition
* short trips - I consider less than 10 miles "short"
* traffic moving at less than 20 MPH; heavy HSD use of EV mode
* low air temps - below 40 degF, HSD will run ICE to keep the Catalytic Converter warm
* use of heater/defrost, HSD starts ICE at stops when coolant temps fall below 145 degF
* water on roadway - 1-5 MPG hit from just barely damp to standing water
* Extra weight in car - junk in the trunk
* "Winter gas" (where applicable)

Other things to consider:
* Dirty throttle body
* Dirty MAF sensor
* Clogged air filter
* Grill blocking
* Electric Block Heater (EBH)
* Dragging rear brake shoe - very rare condition
* Alignment - rear axle misalignment is rare and difficult to fix
* Learning/applying the standard, "low hanging fruit" high MPG driving
methods:
. - "Driving without brakes"
. - Gliding
. - Pulse and Glide (P&G)
. - Minimal/zero use of driver-selected EV mode

Last but not least, installing a ScanGauge to monitor ICE and HV
battery operating conditions helps to take advantage of conditions
where HSD algorithms leave a little operator discretion.

 

Right Rokeby, people sometimes miss the fact that a hybrid is still a car, not perpetuu mobile .
On the other side, it is true that for all the new technology some of the dealers know less then the owners, so the user simply must become an enthusiast, perform researches and rely on other owners experiences. The most frequent response from the dealers is "pay for diagnostic..... everything is in perfect order".

I wanted to ask you...
You said in your post to consider:
* Dirty MAP sensor
Can you explain to me where is this part located, when and how it should be cleaned?

 

"MAP" is a typo. My mistake.
Thanks for pointing it out.
I've fixed my earlier post.

I meant to say MAF sensor.

Here are two threads that give the lowdown
on its location and details on cleaning:

Throttle Body Cleaning

Mass Airflow Sensor (MAF) Cleaning

 

The Energy Saver A/S is a North American model. The Energy Saver + is similar to the North American version of the Energy Saver summer tire. I don't believe they have a Euro equivalent of the A/S. The Energy Saver + is a good tire but be careful which exact model you choose. There appears to be a few different versions within the same size category. I'm at work but I can check for you sometime tomorrow or if you ask John I'm sure he can tell you the specific model you need.