Average MPG calculator accuracy:

[Moon]

I just started a new job about 30 miles from home, so I figured it would be as good of a time as any to see how accurate the average mpg calculator was in the hooptie. I filled up with 87 octane on monday, reset the average mpg calculator console, zero'd out the trip meter, and set off. This morning, I caught gasoline at about fifteen-cents per gallon cheaper than anywhere I'd seen all morning (gasoline prices went up 30 cents here in the last few days) so I refueled and immediately put the pencil to it.

The average mpg calculator said I was getting 23.5 mpg (I generally don't drive faster than 60mph on my way to work).

The pencil said I actually got 21.44 mpg. Not too bad, for a horribly un-aerodynamic vehicle with a six cylinder in it. There's a little in-town driving in there too, of course, but it's mostly interstate / highway driving.

:cheers:

 

[Dave]

I never manually checked mine against the EVIC.........hmmmmmmmm

Dave

 

[HoosierJeeper]

Never checked mine by hand...I drive only 5 miles, all city in the cold. 14 MPG...

 

[Dave]

Never checked mine by hand...I drive only 5 miles, all city in the cold. 14 MPG...

ledfoot..........................:smokin:

(14 is what my EVIC says around town in this cold weather)
-----------------------
Back on topic......

I will manually check mine if I think about it.

Dave

 

[rockymountain]

My evic says 16. I'm getting 15 when doing the math. If you have stock tire size then the speedo is more than likely over by about 2 mph which will mess it all up. My evic is consistently 1 mpg more than actual and on average my speedo is 1 mph faster than what I'm actually running at. So there's the difference I think.

 

[Ry' N Jen]

Last weekend fully loaded up for winter camping we averaged 18 mpg.
Our friends in their XJ's got about the same. But one's on 33's and the other on 35's!

 

[Moon]

What the heck is EVIC ??

:cheers:

 

[dude1116]

Don't have the on board calculator...but I calculate about 19 or 20 on the highway, 15 in town. Now that it's winter, I've dropped to about 17 highway 13 in town. -____-

I'm convinced the only way to get decent mileage in this Jeep is to draft behind tractor trailers...

 

[Moon]

Don't have the on board calculator...

You're just as well off. It's a funny Chrysler electronic gimmick, but that's about it in my opinion.

:cheers:

 

[dude1116]

You're just as well off. It's a funny Chrysler electronic gimmick, but that's about it in my opinion.

:cheers:

Would be nice to have! Even if I have an inaccurate representation of gas mileage, it's ALWAYS going to be inaccurate. Therefore, I can still get an idea if I'm getting better gas mileage than normal or not.

Is the system in the dash or is it an overhead display or something? I've never actually seen one of these info systems in a Liberty.

 

[Moon]

Would be nice to have! Even if I have an inaccurate representation of gas mileage, it's ALWAYS going to be inaccurate. Therefore, I can still get an idea if I'm getting better gas mileage than normal or not.

Is the system in the dash or is it an overhead display or something? I've never actually seen one of these info systems in a Liberty.

It's on the ceiling, directly above the rear-view mirror. It's neat to play with when you first acquire your hooptie. I'm pretty sure it's just for show, for the most part.

:cheers:

 

[rockymountain]

Outside temp, trip, maintenance counter, change what the key fob does, beep on or off when locking doors, compas.
Yep, just for looks.

 

[iamweasel]

Also shows fuel range, which is what I use it for 95% of the time.

beep on or off when locking doors

I haven't seen that on mine ...will have another look.

 

[TwoBobsKJ]

Would be nice to have! Even if I have an inaccurate representation of gas mileage, it's ALWAYS going to be inaccurate. Therefore, I can still get an idea if I'm getting better gas mileage than normal or not.

Is the system in the dash or is it an overhead display or something? I've never actually seen one of these info systems in a Liberty.

The EVIC is an overhead console that displays a compass, outside air temp, trip mileage, MPG, instant MPG (depending on which EVIC you have), elapsed time, etc. BTW, EVIC stands for Electronic Vehicle Information Center.

There is a comprehensive How-To in the...Um..., How-To section. :smokin:

EDIT: Dang, you other guys jumped on the answer to this one quick!

Bob

 

[Moon]

Outside temp, trip, maintenance counter, change what the key fob does, beep on or off when locking doors, compas.
Yep, just for looks.

Aaaaah. Well what I meant is that the EVIC in my hooptie is hardly ever correct on anything (except maybe the compass. It can be 60 degrees outside, and it says it's 52. It does have a handy "miles to service" menu though, so that's good

:cheers:

 

[KeswickDave]

I think the best way to hand-calculate would be to use a GPS for the distance then calculate that against the fuel pumped. Otherwise you are relying on the Jeep's computer for distance, which as mentioned can be offset by tire size, tire wear and probably even tire inflation. Still will have some inaccuracy on a tank by tank basis because you can't exactly measure the fuel used - one fill could be a little more than another etc but long-term it should be pretty accurate.

 

[GA05SPORT]

My EVIC says 15.2 since one of the kids drives it now I've not done the math manually. Just don't want to be overly upset about the real thing. Of course with it lifted, the front guard, light bar, rack cross bars and full 245/75 16 MTR I should be happy with what the EVIC says it's getting. And the driving is all pretty much suburban running around to school and practices. Parent car ownership *****.

 

[sevenhelmet]

I average 17-19 on the EVIC, depending on the driving I am doing. My calculated gas mileage averages 16-18 at each fill; consistently 1mpg less than what is indicated on the EVIC. I've got a mix of highway and stop/go traffic on my commute, so I'm getting exactly what I expect out of the old girl.

 

[67Customs]

When I manually calculate mine vs. the EVIC, I only get a +/- .2 difference on average.

I find my EVIC to be very accurate.

 

[Moon]

I find my EVIC to be very accurate.

Are you still sporting the factory tire size ?? I suspect that I have a different size tire on mine, and that's what's causing the problem.

:cheers: