Does your car have a trip computer? Do you use it?

[Beelzebubba]

I'd be interested to hear from others whose vehicles have a built-in trip computer that calculates fuel economy, distance to empty and similar fuel-related data. Do you use this information to monitor your real-time fuel economy or do you prefer some other method?

It seems these calculators/computers are becoming more common, even showing up in some lower-end econo-cars. In reality, they probably make a lot more sense in a car designed to save fuel rather than the luxury cars and SUVs where they first appeared.

[Dave252252]

I have a 3 year old BMW 3 series diesel (im in the uk), it has a 'current mpg gauge'. Shows real time mpg, so basically I try to keep that pointer above 50mpg at all times, even when accelerating ( just do it slowly ). When cruising I try to keep it above 60.

Its slow progress sometimes, but what would you do with $12+ fuel?

[theholycow]

I had one back when gas was at a historical inflation-adjusted low of under a dollar in the late 1990s. I used it but I didn't care very much, being 17 and having a job but nothing to spend the money on. I was amused to see it over 70mpg while coasting.

How times have changed...

[Jay2TheRescue]

Originally Posted by theholycow

I had one back when gas was at a historical inflation-adjusted low of under a dollar in the late 1990s. I used it but I didn't care very much, being 17 and having a job but nothing to spend the money on. I was amused to see it over 70mpg while coasting.

How times have changed...

LOL, same here. In the 80's when I would drive my mother's Chrysler LeBaron I would do EOC, not to save money... I wasn't paying for gas in that car anyway. It was just cool to see the display flash 99 MPG.

-Jay

[67 Satellite]

My 2004 Dodge Ram has one. It doesn't give a continuous readout but gives an average from whenever you hit the reset until you reset it again. I have found it to be the most accurate when you travel long distances between resets without starting and stopping the engine. If you fill up,reset,make a number of short trips starting and stopping the engine several times,it can be off quite a bit vs. "actual miles divided by gallons used" method.If you fill up,reset,drive a couple hundred miles,then fill up,it will read within a couple of tenths of a mile per gallon of the miles divided by gallons method.

[GasSavers_Pete]

Yeah , my car has one as well and it is surprisingly accurate...down to 0.01 litre per hundred kms.
It has two modes: one is "instant" and the other is "average".
The instant has been known to cause people to watch the numbers and not the road so it defaults to "average" and needs to be reset to "instant" if you really want to know.
Watching on the freeway it is interesting to see how much of a difference things like gradients , crosswinds , other traffic and the like actually make.

Pete.

[trancosrt]

My "econobox" (Mitsubishi Lancer) has one. I mostly use the instantaneous MPG to keep my foot in check and the average (it keeps tracks of the last 4 hours as it is right now) to "compete" with myself on my commutes to beat (or at least attain a high plateau). All in all, I consider them pretty useful even though they are not really that accurate.

[GasSavers_rGS]

A family member owns a car that has one of those trip computers on it. The family member thinks attempted hypermiling is stupid so my family member usually drives fuel inefficiently. When I drive that car using fuel efficient methods while using the trip computer during cruise on the highway, I get that inner glowing happiness when the _average_ fuel economy value that's currently calculated by the trip computer starts ticking up and up and up while I'm driving it. Keep in mind that this is my one fuel efficient driving trip versus the overall fuel inefficient driving that my family member does is resulting in the overall AVERAGE fuel economy to go up and up and up.

[Lug_Nut]

Originally Posted by Pete

Yeah , my car has one as well and it is surprisingly accurate...down to 0.01 litre per hundred kms. Pete.

That's resolution, not accuracy. Different concepts.
I have a stopwatch that displays to .001 second, but if let running gains 10 seconds a week. It has a resolution to .001 seconds but is not as accurate as I expected for an electronic time device.
I also have a tall clock that keeps time to within an amazing 2 seconds a month, but ticks each 3 seconds. The 3 second resolution is only 1/3000th that of the stopwatch, but that clock's accuracy is 20 times better.

I personally think a simple + or - to indicate whether present (nearly) instantaneous economy is better or worse than the average since re-set is all that is really needed.
For MPG, the + indicates more miles and better fuel economy.
For liters per 100km the - indicates less fuel and better economy
That way there's no complacency once some level is reached. The better the "instant" economy, the higher the average becomes thus constantly moving the goal and forcing better and better technique.
You'll still have to calculate the distance traveled and the fuel consumed yourself, but you should do that anyway to check the accuracy of your onboard display.

[ihatemybike]

Green has the info center, I keep the current MPG displayed on it. The fuel consumption on it is usually a gallon high per full tank, so it's avg MPG is a little low. I've been running a SCII for a couple months now, I display RPMs, throttle position (lets me know if a hill is good enough to neutral coast down), trip avg MPG, and current gallons per hour. Using these gauges I've been sitting about 45% above EPA without any hypermiling vehicle mods.