OTIS Accuracy

[tan's2002kjlimited]

Filled up the tank again today (cost me my first born), and checked the paper log I keep against the Otis mpg.
Otis said 17 mpg, where as paper log said 16 mpg. My synapse are better than silicon and copper wire calculator
so I'll contunue to keep a log for accurate mpg averages.

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Chicago, the land of the U.S.A.'s HIGHEST gas prices! Gotta love it!

 

[Gont]

Yea, gas prices suck. Cost me $78 to fill up my tank here

 

[Dave]

Gotta get a CO-ROLL-A............they don't flex much but little cars use less gas than Jeeps. Course, then you'll be feeding 2 vehicles.

Anyway, so you got 1 mpg less on your own calculation than what the Jeep is telling you? I'll have to check mine. Now you got me curious.

What is that pic??

Gas prices around here are between $2.95 and $3.06 today depending on brand.

Dave

 

[tan's2002kjlimited]

What is that pic??

An artist's rendering of a synapse, Deep inside the brain, a neuron prepares to transmit a signal to its target. The brain contains billions of neurons, whose network of chemical messages form the basis for all thought, movement, and behavior.

 

[JeepJeepster]

I filled up for $30 today..

Gas was $2.74..

The evic will always calculate the mpg alittle different. Idk what its doing when youre sitting and idling. Does it calculate the mileage only when the jeep is moving? Or also when idling?

and may I ask what the brain has to do with gas?

haha, I put $16 in the corolla the other night and it took it from a 1/8 tank to 3/4 tank. that will last around 250miles or so.. 300-350 on a full tank. She gets around 30mpg..

 

[tjkj2002]

The overhead computer is not very close at all,better to do the old way of dividing the gallons used by miles driven to get a acurate MPG rate.The overhead computer is just a novality item anyway,the temp never reads right either,and the compass is inaccurate anywhere with large metal objects around.Just more of a general idea then anything else.

 

[06Liberty]

We went on a trip a month ago and had to follow my mom and stepdad. They were driving their '05 Limited KJ 2wd with the evic thing and we were driving my '06 Sport KJ 2wd. We both filled up before we left, and reset the trip odometer and evic and when it was time to fill up again I got 24mpg to my tank and the evic said my mom's got an average of 19. I still don't know why it's different, but it is.

 

[Dave]

An artist's rendering of a synapse, Deep inside the brain, a neuron prepares to transmit a signal to its target. The brain contains billions of neurons, whose network of chemical messages form the basis for all thought, movement, and behavior.

Well that explains it. My neurons were telling me it was time for a drink and so the picture didn't compute. Now that I have that drink it's all coming in clear.

Dave

 

[Gont]

You guys have cheap gas! I'm payin $5 a gallon!

 

[Dave]

You guys have cheap gas! I'm payin $5 a gallon!

Wow, I knew it was higher in Canada but I didn't realize it was that high. You must have a high tax structure on it too. Does some of it go to your national health care system?

Dave

 

[Marlon_JB2]

OK, the one thing about the EVIC is... I actually trust it more than hand/brain calculations.

Why? It's computerized. Pumping and calculating is not. Each time you go to the gas station, something different happens which may change your MPG measurements.

With that said, mine is spot on, with maybe a half a MPG or so difference.

 

[Gont]

Wow, I knew it was higher in Canada but I didn't realize it was that high. You must have a high tax structure on it too. Does some of it go to your national health care system?

Dave

No idea where it goes, but its $1.20/liter in Saskatoon today.

 

[Dave]

We went on a trip a month ago and had to follow my mom and stepdad. They were driving their '05 Limited KJ 2wd with the evic thing and we were driving my '06 Sport KJ 2wd. We both filled up before we left, and reset the trip odometer and evic and when it was time to fill up again I got 24mpg to my tank and the evic said my mom's got an average of 19. I still don't know why it's different, but it is.

That is a lot of difference. Different driving styles and other small variables I guess. 24 is really good for a KJ I think. The best mine will read consistantly on the average is 21.5 or so with mostly highway. If I reset mine on a flat highway at 70 it will get to 24 but won't stay there long.

I drive some mountain roads and coming down this one long downhill grade with o/d locked out so I wouldn't have to brake I started out at the top at 55 and reset the thing and coasted all the way down in drive without giving it any gas and it stayed at 99.9 until the road leveled out at the bottom and I was going 75 but then it started going down very quickly as the road leveled out and I slowed to 60 and I went back to o/d and gave it gas. haha. It stayed at around 23-24 for a couple of miles and settled at 22 then back to 21.5 or so after a while. So it seems sensitive and working. Around town it's much less. It can be anywhere between 15 and 18 depending on how much stop and go and ideling. In the winter I've had it read 14 something in traffic and snow in full-time 4wd.

Dave

Dave

 

[indianrefining]

You guys have cheap gas! I'm payin $5 a gallon!

Are you talking US or Canadian dollars? And are you converting Imperial gallons to US gallons? (Just playing devil's advocate. Any way you cut it, it's a bunch of damn bucks!)

 

[KeswickDave]

$1.20 CDN / L = $4.53 CDN / US Gal (3.78 L)

= $4.37 USD

In case anyone wondered

I'm paying around $1.00 / L here, which translates to $3.65 USD / Gal.

Dave

 

[JIMMY JEEP]

You guys on that side of the pond should think yourselves lucky it costs me £58.00 to fill up with diesel over here in the uk, rough exchange rate figures will make ya shit ya pants 119 dollars .UK ***** for tax every ten pounds that goes in your tank eight pounds is tax thats 80%, please can someone adopt me in the Usa ,lol

 

[kjpilot]

The EVIC can directly monitor the volume of fuel being consumed & compare it to the number of miles currently being driven... Provided your speedo & odo are accurate. But if the odometer is off, then your synaptic process will be as well.

When you fill up, many variables are going to effect how much fuel is going into the tank. Hot days will put less fuel in the tank than cool days, how the shut off trigger is adjusted on the various pumps you use, etc.

If you ran your sample tank from full to empty, the error would only be 1.15 gallons. If you filled up at closer to 1/4 of a tank, the error would only be 0.8 gallons. The variables above are more than capable of causing that difference.

I think the EVIC will be more accurate. Noting wrong with the brain, there are just fewer variables with the direct data.

 

[tjkj2002]

The EVIC can directly monitor the volume of fuel being consumed & compare it to the number of miles currently being driven... Provided your speedo & odo are accurate. But if the odometer is off, then your synaptic process will be as well.

When you fill up, many variables are going to effect how much fuel is going into the tank. Hot days will put less fuel in the tank than cool days, how the shut off trigger is adjusted on the various pumps you use, etc.

If you ran your sample tank from full to empty, the error would only be 1.15 gallons. If you filled up at closer to 1/4 of a tank, the error would only be 0.8 gallons. The variables above are more than capable of causing that difference.

I think the EVIC will be more accurate. Noting wrong with the brain, there are just fewer variables with the direct data.

You do have some good points,but if you fill up at the same time during the day and use tha same pump(which I do) then the manual way is way more accurate.Plus the overhead computer is using the fuel level sender to gauge fuel used and I have yet to see a KJ fuel gauge even close to being right(I know mine will say I have 3/4 tank left but put 7-9 gallons in,and I have a 18.5 gallon tank),let alone a gauge on any vehicle.When your fancy computer say's your out of gas and your still driving is a big point to it being not very accurate.Oh and 99% of all vehicle speedo's are off from the factory by up to +/-5%

 

[kjpilot]

The fuel gauge is a different unit all together. If someone wanted to, they could adjust the float so it was close to accurate, but what would the point really be? It's a small gauge with thick lines & a fat needle... looks to be designed by Fisher-Price. Remember, any error in the Odometer system will affect your calculations as well as that of the computer, so this error is not pertinent in this discussion.

The calculation isn't based on when it's empty, full, 3/4, 1/2 or otherwise; it's how much gas is used over the distance traveled. So what the gauge reads also has no real importance to this issue. I'd bet that you are right that the reading that tells us "*** miles to empty" comes directly from the fuel level float. I happen to know in my KJ, I can go about 16 miles past zero, before I'm at zero. #-o

I cannot find in the service manual where the EVIC gets it's average & instant MPG calculation from, but it makes no sense that this comes from the float. First, the engine management computer knows exactly how much fuel it is sending to the engine. Giving that info to the EVIC would be a simple thing to do, It's already designed to give that info to an interrogating computer, why not utilize it? The instant MPG is evidence that the EVIC gets that info from the engine management system. the float in the tank simply cannot tell you if you are getting 15.5 MPG this second & 22.3 the next. The engine management computer can.

Therefore, I still believe the EVIC is more accurate based on the points I listed above.

 

[JeepJeepster]

Mine said I was getting 24mpg at 75mph on the way home this past weekend. It was a 100mile trip home and there is no way I was getting that at 75 mph. I do have the flowmaster and K&N but there is no way it helped that much. I wish I was getting that though..