Prius c gives me 16Km/ltr. Help me.

Try this:

1. Fill the tank, till the pump first shuts off. Note the odometer reading. (Everytime you shut the car down the odometer reading (km's driven since brand new) will display for about 30 seconds, regardless of your settings))

2. Drive the car, till the gas is getting low. There's no need to near-empty the tank, just whatever you're comfortable with.

3. Fill the tank, till the pump first shuts off. Note the odometer reading. Retain the gas receipt indicating liters pumped.

4. Subtract the second odometer reading from the first, to get the km's driven for that tank. Divide that number by the liters pumped to get km's per liter.

 

He's using an old-fashioned load tester. There are a new class of tester, less stressful on battery and better insight. Not sure but I think a drop to 10 volt is acceptable. The initial 12~12.2 volt level is quite low though. Continue to monitor and if it's never higher when at rest, a new 12 volt battery would be warranted.

 

Just for you to get an idea.. I was doing 20-22 Km/L and after the first service its now dropped to 17-18 Km/L but its hot as hell these days and I'm driving in the worst traffic conditions. In the evening my 13 Km journey getting home takes 1.5 hours or more. Its crawl/stop/crawl traffic & have to accelerate to just move couple of feet taking the car out of EV mode or the drivers behind go nuts (you probably can understand this).

Its the worst kind of traffic to drive the Aqua/Prius C. I wish I could get the car to run the engine until at least the traction battery is half full that way it need not run the engine every 5/10 minutes for about 1 minute just to maintain the minimum charge.

About the psi, I was on 33 psi until recently and reduced to 31.5 (maybe that also contributed to the lower Km/L). The car does great at 33 but uneven roads create lot of vibration and noise, also when there are ripples on the road surface you get traction warning.

Do you carry passengers or drive alone. that also will have an impact (due to weight). Do you still have the original 12V battery?

 

A few of factors to consider (many already mentioned in this thread):
#1 Weather. If the temperature is 35C or more, you'll probably be running your AC quite heavily, and that'll impact your fuel efficiency. If the weather is 5C or less, your car will be spending a lot more time warming up the engine, and that'll affect fuel efficiency. I tend to get about 4.4 to 4.6 L/100km over the summer and about 5.1 to 5.5 L/100km over the winter.
#2 The number of passengers in the car (or just the weight of the load in the car). The car itself weighs about 1100 kilograms, so not only will the car handle differently when there's four people in the car compared to when it's just you, but its fuel efficiency will be negatively impacted.
#3 The duration of the trips. It takes time for the engine to warm up, so for the first few minutes, the fuel efficiency will be much lower. Once you've been driving for a few minutes, then your efficiency will be good. If the first few minutes make up a large portion of the trip, then your mileage will be lower.
#4 The tire pressure. I get my tires boosted to 38 PSI every 5000 miles. Higher tire pressure will give better mileage.

Still, it's definitely an issue if you're using more than 6L/100km. You can't really control the first three factors that I gave, so if these are all impacting your mileage, then you'll have to expect to be using more than 5L/100km even if you're doing everything else right.

 

o/p, what does your door sticker recommend for psi? is it the same front and back? mine is 2 psi higher in the front, and i run 40/42, but the c might be different.

as far as the 12v is concerned, 12.2 is a bit low, but if you opened a door to test it, there might be a small drain.

 

Not the O/P but my door sticker says 33psi on all 4, I have an Aqua 2015 the JDM model. Maybe all 4 are equal due to additional weight of the battery (and of course the fuel tank) in the back. It used to be front having a higher rate than back due to engine weight.

You have a plug-in right so no fuel tank? maybe that's the reason for back being 2 psi lower?

 

thanks! i have a 10 gallon fuel tank, but you're probably right about the weight balancing.

still, if the sticker says 33, i wouldn't run 32. i wouldn't even run 33, because you're bound to be lower unless you check very frequently.

 

I run all four tires at the same pressures, just for expedience. Nothing much happens.

A little higher than spec.

 

The local road conditions are not very good even in the city (except for few), with 33 psi the car rattles a lot and sometimes even gives the traction warning when driving on roads with ripples (mostly caused by the hot climate + heavy vehicles). So there is no option but to lower it to 31 or 32.

I have a Tyredog TD1000A-X wireless TPMS installed to warn me when the pressure becomes low and a Ring Digital Tyre Inflator to save the day.

 

all good points, thank you.

 

TD 1000A-X is an old model, I bought it in 2010 from eBay. Do a search on eBay for TyreDog there are newer models. Also there are internal sensors & external sensors (I got the external type so I could install it myself). You can also check out SteelMate, that a good brand too.

BTW does your car come with a spare wheel? If its an S or G it wont have a spare and that's a real headache. Been hunting for one from the day I bought the car and still no luck

 

Yes.. that piece of garbage. Keep an eye open for a spare too. The original spec for the spare is (as mentioned in the door sticker) T125/70D16 96M. If you end up with a flat late at night when tire repair shops are closed or when you are out of the city you might have to abandon the car. Also that bottle is single use and pretty expensive to replace (at least in this part of the world).

The tire repair kit is effective if the damage is limited, also from what I have heard you have to wash and clean the liquid from the tire/rim before applying the permanent puncture plug at a tire repair shop. So that's another messy process.

 

The "Range" meter after fill is an estimate. Your real world kms out of your tank will vary based on driving conditions/style.

 

Salaam,
If you are driving in Pakistan, the weather will be a factor. What kind of tires do you have? Are you driving on dirt roads? Or actual blacktop roads?
What city in Pakistan?