Gas Gauge And Gasohol

[Tywais]

Due to the lack of 91 benzene I filled my last tank with gasohol 95. I always reset my trip odometer when filling up. This is a 2+ year old Civic 2.0 with all digital panel including a bar graph style gas gauge. I noticed that towards the bottom 1/4 or so the gauge was not matching my normal usage based on the odometer. I figured as it is gasohol there will be a slight reduction in mileage but this was in the neighborhood of 15%.

My standard usage is that the reserve light goes on at 400+kM. This time it went on at 350kM and had me concerned. But after filling up, the km/liter was exactly the same as always which means a difference in how the gauge is measuring it with gasohol. Many years ago the gauges were based on a 'float' device but believe modern cars are on capacitive sensors. Shouldn't these auto-calibrate? I just found a station with 91 benzene and filled up with that and will see how the gauge does with it.

A bit annoying in that I can't rely upon the gauge for accurate fillup time. At least it shows less gas remaining then in actuality, the other way around would be even more annoying. Anyone else experience this?

[harrry]

Doesn't the computer calculate the milage left on the basis of existing milage. Gasahol gives less mpg than pure benzin so as it calculates it will show lwss miles available. When filled it will show the standard factory figure as range.

[Tywais]

Doesn't the computer calculate the milage left on the basis of existing milage. Gasahol gives less mpg than pure benzin so as it calculates it will show lwss miles available. When filled it will show the standard factory figure as range.

My car doesn't have the mileage calculator in it, I use the digital trip odometer and the amount of gas to fill it up to calculate it manually. In other words, standard low tech method.

[harrry]

Doesn't the computer calculate the milage left on the basis of existing milage. Gasahol gives less mpg than pure benzin so as it calculates it will show lwss miles available. When filled it will show the standard factory figure as range.

My car doesn't have the mileage calculator in it, I use the digital trip odometer and the amount of gas to fill it up to calculate it manually. In other words, standard low tech method.

You mean the car has a sly drool

[Tywais]

You mean the car has a sly drool

Ok harrry, you made me have to use Google - Sly drool - "slide rule; instrument used by engineers for discovering Kew brutes and for making other calculations"

Been a while since I've used those. Bamboo version was the best I found.

[WarpSpeed]

I'm with Harrry on this one, it seems it has calibrated to the mileage of gasohol, even if you don't have a mileage calculator accessory that you can physically read doesn't mean the ECU doesn't have that programmed into it to compensate automatically.. The ECU will read your mileage based on it's own figures and calibrations accordingly reading all sensor measurements across a wide range to determine the fuels estimated mileage which in the end it will compensate for in remaining mileage notification..

Personally I hate those bar graph fuel gauges as there is no way to actually estimate how much is being used between bars and how much is actually there, terrible if you're renting a car with one and have to try to estimate how much to refill when you return it without over or under filling it.

Edited February 16, 2013 by WarpSpeed

[Tywais]

So what you are saying is that the gas gauge itself is being re-calibrated, effectively re-estimating, how much gas is in the tank? That is the only variable that could change as I mentioned I'm using the trip odometer which is not related to gas levels. Quite an inaccurate re-calibration it would seem then. The gas mileage itself had not changed based on the odometer reading and the quantity of gas filled up, nearly identical from using 91 benzene. There is no remaining mileage notification, only remaining gas notification via the bar graph and the reserve light coming on.

[Kwasaki]

Don't know about his fuel gauge but a Thai friend has a 2010 Civic 2.0ltr always run on 91 gasohol no problem.

Put 91 benzene in the wife's Yaris from time to time and now it's gone we just stick with E20 can't say I notice any difference though.