calculated vs. computer MPG - Please post your results

Many years ago, when our kids were young:

Driving by some gas station with a promotion on, some kids' toy, and my son (about 8 at the time, 40 now) pipes up: "say, are we low on fuel?".

I'd suspect the filter's about the same size, just the funhouse wide-angle of the iphone lens, coupled with close-up, makes it look huuuge.

 

Mendel Leisk, I just purchased a 2010 Prius IV from a dealer in Marietta, GA. 61,000 miles. The vehicle has been dealer maintained. They provided a full service history. I'm prepping for a trip to the Pacific Northwest (Boise, Idaho) in November. Is a Prius up to a long trip (2,200 miles) in potential winter weather? It has Michelin Defender All Seasons with adequate tread. There is no history documented in the service history of the excessive oil consumption issue mentioned on PriusChat. The 60K mile service was completed. This is my first hybrid.

 

If they've got deep tread you should be ok. You're really asking the wrong guy though: our Michelin X-Ice go on every fall, come off in spring. Our coastal climate is relatively mild. Once you get into the interior snow and ice is more the norm.

I used this rim and lug nuts, 100% compatible (and no tpms sensors, just ordinary valves):

Corolla steel rim, part no: 42611-02471 (2003-2008 corolla or matrix, CE, LS, S)
steel rim lug nuts, part no: 90942-01007 (plain, open-ended, galvanized)

I'd check the dipstick regularly, always a good practice, more so with a new-to-you car with some miles. Dealership can easily miss oil consumption: and it's really the owner's responsibility, to monitor and top up. Dealership service departments have large waste oil catching containers: the oil goes in and there's no way to verify the drain volume. They might check the dipstick before draining, but that's not really in the job description.

I've found if I pull the dipstick and immediately reinsert for a check, it's hard to read. The oil seems to get drawn up the tube with that initial pull out, then smears along the dipstick edges, making the true level hard to read. A solution is to pull the dipstick, then wait at least 5 minutes, say check tire pressures while waiting. With that wait the reinserted dipstick comes out much easier to read.

Our 2010 is the first car we've had with near zero oil consumption, I'm a bit surprised. But owner's here report various amounts of consumption. With cars we've had in the past, I'm more used to having to do a top up, mid way between oil changes, anywhere between a cup and a quart.

 

As a native of the Pacific NorthWest interior, I must say that the car is fine if you are on primary roads, it is just a matter of tires.

'Adequate tread' is not a sufficient description. What is the actual tread depth? I have those tires on mine now, but my experience with prior All Season tires is that they lack adequate winter traction for my tastes when the tread reaches half the original depth. Then they must be exiled to 3-season use.

Now I use true winter tires (currently Michelin X-Ice) for real winter, December-February. November is early enough that full winter tires are usually unnecessary. But be wary, especially from Thanksgiving on, as early weather surprises do happen. You might want to adjust route or schedule if serious weather strikes. E.g. wait out the worst weather for a few days and travel when it abates.

But a disclaimer: my travels in the interior PNW go well off the primary roads and to places lacking ground clearance and winter plowing. My core winter travels are now in a Subaru, not in my Prius or its 2WD predecessor.

 

Itn city it gets to 7% on road 2-3%, like if my computer shows 4L/100 km, it could be 4,3L/100km. Summer time! Winter period not tried yet.

 

Same here, you can add 0.3 to whatever the dash shows, and nine times out of 10 you have it right. Once in a while 0.4.

I never get that low though, more like dash says 4.6 and calculated is 4.9.

 

Excellent! Thank you for sharing your Prius wisdom with me!

 

Excellent! Thank you for sharing your Prius wisdom with me! I narrowed my Winter tire choice to the same Michelin X-Ice tires that you and another helpful poster purchased. Where did you purchase your Corolla steel rims? Dealership? Junkyard? New? Used?

 

New, through a dealerership. Our local dealership told me the only Toyota option for rims would be 3rd gen 15" (alloy) rims, for $350 apiece. I emailed every dealership in town, and one other dealership responded saying they "thought" these Corolla steel rims would work. They were new, $70 apiece, and the plain lug nuts $31. I let them handle the complete thing, including tires, just in case there was a fit problem.

This was in November of 2010, and with our low miles still using them, they have about 8/32" tread depth still. At least a winter or two still before they'll need replacement I think.

One thing: the car's hubs rust up fast without a center cap. I found an 2" ABS pipe end cap is almost a perfect fit. It has an I.D. of 2-3/8". To fill the slight gap I push on a rubber band made by cutting a section out of old bicycle inner tube, then push the cap on.

Another thing that's rust-prone is the tips of the wheel studs, due to the open ended lug nuts. I've resorted to a drop of oil on each (say 3-in-1 oil) and brush it around a bit. Once or twice during the winter is enough.

Overall funky, but it works:



I do have some much nicer Plug-In Prius rims, when it's time to replace these I might switch over.

 

Excellent! Thank you!

 

Thank you
For sharing your Prius wisdom with me!
I narrowed my Winter tire choice to the same Michelin X-Ice tires that you and another helpful poster purchased.
Where did you purchase your Corolla steel rims?

 

In my ride, the computer is always 2mpg more positive than what is hand calculated. Always.

 

I've had my '15 Prius for sixteen months but only put about 5,500 miles on it (now at 60k miles). On the last tank it was at 52.8 mpg (US gallons) vs. 56.0 as reported by the car. Overall I've found a difference of 2.5 mpg between the two.

 

5th time I checked my 2012 prius (japan), when computer shows 4.0L/100 km real calculation is 4.3L/100 km. We have to know its not only car computer it depends how exact is gas station !!! If gadget on gas station has also 1 -2% failure we get 3 -4 % dissmiss.

 

My 2005 Chrysler Town and Country is pretty close especially over time. Of course in all my driving we are talking about 23 to 24 mpg and not 48 to 52 so that may have something to do with it.

 

No, it does not

All the posts I have seen about prius are with over optimistic, not to say lying computer

This is clearly intended, as the fuel consumption in obd 2 apps is accurate

 

On average 2-3 mpg less than computer..

 

Ok so we have a 2012 Prius V Wagon, we have filled it many times and only get DTE to empty says 650 kilometers to empty. We would put in about 34 or 35 liter at this point. Not happy with the fuel economy I decided to put a small jerry can of gas in the back and drove it to 0 Km to empty. 672 km, but it kept going and we drove it to 745 km before stopping for fuel. NOW here is the weird part Toyota says it has a 11.9 Gallon tank, convert that to liters and lets just round up and call it 12 gallons , and lets say a gallon is 4 liters rounding up. so
12 gallons x 4 liters = 48 liters of fuel on board. How did we manage to put in 53 liters of fuel?

Part two. Is their a way to reset or train the computer to read the proper DTE, instead of the standard just 650 km? Also can't get the Fuel economy below 6.0L/100 km no matter how I drive it.

 

Just disconnect the 12V battery ground for a couple minutes and the DTE calculator will go back to factory. But, of course, it won't let you drive any farther on a tank of gas and it will soon re-adapt to current conditions.

If the pump said you put in 53 liters, that's 14.00111877 US gallons. You was robbed!! I'd complain to the gas station owner and/or whoever in your provincial government is supposed to be checking the gas pump accuracies.