DaveofDurham

Generalbeluga - Good to hear from you! The CR overall score and the CR reliability rating are two different things. Overall score -- "The overall score for a tested model is based on CR's results from more than 50 tests and evaluations. You can easily see how its overall score compares with the "Highest" and "Lowest" rated vehicles in its category." "Formal testing is done at the track and on surrounding public roads. The evaluation regimen consists of more than 50 individual tests. Some are objective, instrumented track tests using state-of-the-art electronic gear that yield empirical findings. Some are subjective evaluations-jury tests done by the experienced engineering staff." Reliability rating -- See http://www.consumerr...ories/index.htm for CR's explanation of its "Reliability" ratings system. Note they say "Models that score a are not necessarily unreliable, but have a higher rate of problems than the average model. Similarly, models that score are not necessarily problem-free, but had relatively few problems compared with other models." They also say, "Consumer Reports subscribers reported on any serious problems they had with their vehicles during the past 12 months that they considered serious because of cost, failure, safety, or downtime, in any of the trouble spots included in the table below." Sincerely "Ferris Bueller"

From today's ABA Journal News - Electric-car owner [Judge] Alex Kozinski offers ‘scathing’ objection in class actionhttp://www.abajournal.com/news/article/nissan_leaf_owner_alex_kozinski_is_scathing/?utm_source=maestro&utm_medium=email&utm_campaign=daily_email

I spoke to someone at the NC Dept of Agriculture, Standards Division, Measurement Section this afternoon. I asked him how much variation is allowed when gas pumps are tested. He told me that the same standards apply throughout the US. These standards are presented in NIST Handbook 44 which is adopted by the Nat'l Conference on Weights and Measures. This handbook is available online at In NC the testing is done using a calibrated 5 gallon container. The permissible variation is described in table T.2 on page 3-20 of the handbook - see the statement after the * at the bottom of the table (the statement after the * is for "test drafts" less than 10 gallons). For a new pump or a pump refurbished within 30 days of testing the permissible variation is +/- 3 cubic inches per 5 gallons (meter reading on the pump). One gallon is 231 cubic inches, so 5 gallons are 1155 cubic inches and +/- 3 cubic inches is +/- 0.26 percent. For a pump in service for more than 30 days the permissible variation is +/- 6 cubic inches per gallon which is +/- 0.52 percent. So, the permissible variation at the pump is much less than the variation we are seeing between the pumped gallons and the car's report of gallons used. Here is a video from a company in Canada about a more modern and sophisticated way to check pump accuracy.

What characteristic of pure gas (compared to a gas/ethanol blend) or of the smart gauge system do you think could/would result in the smart gauge being more accurate for pure gas than for a gas/ethanol blend?

What is RDS? I get the artist/song info sometimes and sometimes I don't.

Does your state require that gas pumps adjust fuel volume for temperature of the fuel? While searching for some info about how accurate gas pumps are supposed to be, I found several places that said that in the US the pumps do not adjust fuel volume for temperature of the fuel and that in Canada they do. In defense of not adjusting, there was a discussion of how/why the fuel temp does not vary that much because of underground tanks. I am going to check with someone in Raleigh on what the NC regulations are for fuel pump accuracy. I know from their website that the check is done with a calibrated 5 gallon container and that the container is filled twice (one rapid fill and one slow fill) to check that the pump is within the required accuracy.

Fascinating. I looked at a province by province list and found that BC, Manitoba and Saskatchewan each have gov't insurance corporations. Quebec has a mix - gov't does personal injury and private co's do property damage. All the others have private insurance companies.

Can you get the "State Farm Discount Double Cheque" in Canada? It would make your Ford cheque "Go Further".

Ouch!!! Glad you are ok. Take care of yourself while your insurance and body shop are caring for your C-Max.

Pedestrians get great MPG.

I get the better MPG with pure gas than with a gas/ethanol blend. Gasoline has higher energy content than ethanol, so pure gas gives better MPG than a gas/ethanol blend. What I have been trying to understand is [1] how much data (how many fill ups with pure gas) you have to lead you to conclude that there is better agreement between the gallons used per the trip odometer and gallons added per the pump when you use pure gas than when you use gas/ethanol blend AND [2] why there would be better agreement between the gallons used per the trip odometer and gallons added per the pump when you use pure gas than when you use gas/ethanol blend? If you have only filled up with pure gas 3 times then it seems to me that you don't have much info to go on to conclude that there is better agreement between the gallons used per the trip odometer and gallons added per the pump when you use pure gas than when you use gas/ethanol blend. I have only used gas/ethanol blend. Sometimes I get very good agreement btw the gallons used per the trip odometer and gallons added per the pump, frequently I pump more than the car says I have used and sometimes I pump less - over 43 fill-ups the car says I have used 4.7% less gallons than I have pumped.

How many fill ups have you done w pure gas and have they all shown better agreement btw the gallons used per the trip odometer and gallons added per the pump? What difference btw pure gas and ethanol/gas blend do you think leads to better agreement with pure gas than with ethanol/gas blend?

Fascinating. By trip meter do you mean the individual drive (trip meter) that comes up on the small left screen when you turn the car off when you get to your destination OR do you mean the trip odometers?

Thanks. What does >>>"Fuel consumed" is continuously calculated based on PCM fuel pulsewidth summation as a percent of fuel tank capacity.>>> mean and how is "pulsewidth" converted to gallons?

Jason - Congrats on the new C-Max and welcome to the forum. You will find lots of great information and helpful C-Max owners here.

I totally agree that the information used by the car to calculate miles per gallon is the car's measurement/calculation of miles driven and the car's measurement calculation of gallons of fuel used. Several posters have stated in other threads that they found that the car's odometer read 1.5% less miles traveled than did their independent (i.e., not the car's) GPS. Assuming that the independent GPS units are correct, this 1.5% error in the car's odometer would depress the car's calculated/estimated mpg figures by 1.5%. In regard to gallons of fuel used, several posters have stated in this and other threads that they add more gas when they refuel than the trip odometer reports they have used since their previous fill-up. I have looked at my lifetime history over 11 months and 18,000+ miles. The gas the car says I have used (odometer reading at last fill-up divided by lifetime mpg at last fill-up) is 4.7% less than the gas I have put in (sum of individual pump numbers). What I do not understand and have not been able to figure out by searching around the web, is how does the car measure/estimate fuel use. From my web searching, it appears that the car may start by counting pulses of the fuel injectors and then combine this with a fuel pressure setting or measurement and perhaps other data or constants/factors to come up with its very short term (almost instantaneous) measure/estimate of fuel use and then keep a running sum of these individual values to come up with its measure/estimate of longer term (e.g., from fill-up to fill-up, from trip odometer reset to trip odometer reset, or lifetime) fuel use. Can someone who understands the inner workings of the car explain how the car measures/estimates fuel use and what factors are causing the long term spread we see between the car's info (lower) and what we add at the pump (higher)?

Do you know why there is better agreement between the gauge and the pump for pure gas than for an ethanol blend? One factor could be the difference in specific gravity between gasoline and gas/ethanol blend - if the way the car estimates fuel usage is to somehow measure the mass used and convert the mass to volume using the density of gasoline (thereby underestimating gas/ethanol blend use since the blend is denser than gasoline). Ethanol is denser than gasoline, 790 grams per liter for ethanol versus 730 (on average) for gasoline but that alone would not explain the discrepancy between the gauge and the pump for a 90/10 or 85/15 gas/ethanol blend. [see graph on page 7 of document at http://www.txideafarm.com/ethanol_fuel_properties_and_data.pdf ]

I know about the BTU difference between gasoline and ethanol, and how it results in reduced MPG for ethanol blended gas compared to pure gas. I thought you were saying that with pure gas you have seen better agreement between the trip odometer's report of gallons used and the gas pump's report of gallons pumped than you do when you run your car with a gas/ethanol blend. Did I misinterpret your post (#4 in this thread)?

Paul - Are you saying that when you run your car with pure gas (no ethanol) that you get better agreement between the trip odometer's report of gallons used and the gas pump's report of gallons pumped than when you run your car with a gas/ethanol blend? If so, how close is the agreement when you run with pure gas and why do you think there is a difference in the spread when you run with pure gas vs. when you run with a gas/ethanol blend?

My wife noticed the taxi, but didn't realize it was a C-Max. In the words of Warner Wolf, I will have to go to the videotape (or in today's parlance the DVR). Q: When you came up with "Let's go to the videotape," what was the story behind it? A: When they first put me on television it was about 1969. There wasn't too much videotape then. We mostly shot our own games with film. Through the late-night syndication, it was a Warriors-Bucks game. Kareem Abdul-Jabbar was going against Nate Thurmond. I said, "The Warriors led 98-90 in the fourth quarter and look at this defense that Thurmond puts on Jabbar." No tape came up. So I said, "You have to look at this exchange between the two of them, between Nate Thurmond and Kareem." No tape. Finally, I said to the director in the booth, his name was Ernie Bauer, "Ernie, lets go to the videotape." And the tape rolled. After the show, Ernie came out and said, "Warner, that's great. I'm doing 25 things in there. When you said, ‘Let's go to the video tape,' I immediately punched it up. So do it again tomorrow night."

Take a look at the "C-max MPG not calculated correctly" thread for a recent and ongoing discussion of trip odometer reported gallons used vs pump reported gallons added. My difference over 18000+ miles and 40+ fill-ups is 4.7% (pump gallons greater than trip odometer gallons). This is just about the difference you have on your 600 mile trip.

Your difference between trip meter gallons used and gallons pumped is close to twice what mine is. One thing to check after you fill up is whether you see any signs of gas dripping onto the ground in the vicinity of the filler neck. I had this happen 5 years ago on my Honda Odyssey. There was a leak in the filler neck - so right after filling up we would be dripping gas until the level got below the point of the leak. The Odyssey was 12 years old when this happened. This is less likely in a new vehicle, but stranger things have been reported in this forum.

At my 43rd (last) fill-up, my odometer was at 18,445 miles. According to my car, my lifetime mpg is 43.5 which equates to 424.0 gallons of gas used. According to my fuelly records (which have the gallons added according to the pump), my lifetime mpg is 41.4 which equates to 445.5 gallons of gas used. So the running gas used total according to the car is 4.7 percent less than the running sum of the individual pump values. This is an average of about 0.5 gallons on a 10 gallon fill-up. Of course this only addresses variation in fuel usage. Months ago there were some posts about the difference between the miles traveled per the odometer and per independent gps. For example, the thread titled "It Looks Like everyone is getting 1.5% Better MPG's than they think they are!" which indicated that the gps showed about 1.5% more miles traveled than the odometer. Has anyone looked at this more recently?

I tried wab's test. I got same results w car running. I got some different results in accessory mode. See red text below.

Laurel - Reading your wonderful piece of family history reminded me of this famous photo: Putting a C-Max term to a different use, what was their "sweet spot" (meeting place) in NYC?