Hi everyone,

I've just learned how to get the fuel consumption screen up on my car, so I tried it out today on a 30 mile round trip, averaging about 40 mph, and either it isn't functioning properly or my driving SUCKS, because the mileage is awful....I got an average of about 13 k/l, which I'm working out to be just over 31 mpg....that seems horrid. I don't drive agressively, I've been coasting when I can, so I can't understand this horrible efficiency. Help?

Can you describe the environment a little better. Was it cold, how cold exactly? Are you driving up mtn roads, hilly roads? Or is it all flat? Are you towing anything, is your car packed? How many people? Has there been any modifications made to your car? OEM wheels, exhaust?

It was 22 celsius, 71 fahrenheit, some flat bits, some hilly roads, not towing anything, car's nearly empty, only 2 passengers, no modifications. I just can't understand it.

How long have you owned this car? Do you have the complete history? Has the car been in an accident? What tires do you have? Have you checked your tire pressure? Try going +5 psi over recommended.

What gas are you using, try switching gas. Go to a heavy volume gas station and fill up there. Maybe you have water in your tank.

We've only had it since last Thursday, it's a Japanese import so we don't have any real history on it, just the dealer's word that it's a good car....it only has 23,000 miles, so it should be in good shape. Not sure what the tires are, but I just filled them up to 42/40 a few days ago. We're just using regular unleaded gas. How would we have gotten water in our tank?

Well water can come from a station's tank. There are many ways for a station to get water in the tank, but typically a high volume station will not have any moisture because the turnover rate will prevent it (dillute it quicker, or not have a chance to allow moisture to form).

Anyway, try changing stations and keep using regular unleaded.

My one advice that I always give to everybody new to hybrids is to feather the gas pedal. By that I mean, use it sparingly. Where as in your typical car you kind of mash the pedal to go, in a hybrid you want to ease into the gas, once crusing, you want to barely touch the gas.

To fine tune this technique, look at your instant feedback meter. As you see your k/l drop, try to ease off the accelerator, as it climbs try to ease into the gas to get more momentum. You can really gain on hills with that technique, on flats, it's a matter of finding the sweet spot by looking at the k/l meter and try to find the gas pedal position that achieve the highest k/l for the given speed.

After a while, this will all feel very natural.

Also... trying doing some searches here. There are plenty of people that have experience with the Prius here. I'm actually shocked nobody has come to the rescue here. Maybe wrong forum? Try and see (get a moderator) if you can have this thread moved over to the Prius forum.

The 1999 NHW-10 original Prius is for Japanese market only.
No dealer technician was trained to maintain the Prius outside of Japan. It is very special hybrid vehicle and we never know what is the root cause of your low mpg.
What kind of warrany do you get from the dealer?

Ken@Japan

Hello from Fuji in Japan(als known as cuchulain on cleanmpg.com)

As an Irishman driving 99NHW10 Prius, I have been typically obtaining 23.5km/l or 55mpg US.

First question is it set at Full A/C, in this mode the engine will not auto shut-off. I almost never use A/C but if I need to use the A/C switch not full A/C.

When you switch on with A/C off you should see the battery charging in the consumption screen, if it is not charging, the battery will be at red. Also there will be a turtle mark appearing to the left of the speed odometer. Then you most likely have a NiMH battery problem.

Another possibility preventing engine cut off is a Pt wire sensor which has become dirtied during transport. This can be cleaned.

I hope this is useful.

Andrew

Andrew

Andrew