Quallcom says I'm getting terrible MPG

**transam pete** · 07.01.2012

if my response was terse i am sorry. too many years of listening to my engineer father tell me without all the facts no accurate determination can be made
quall coms are nothing more then computers programmed by humans to do tasks for us faster then we can manually
wonderful inventions except for that HUMAN part so BS in means BS out

**Kroozn20** · 07.02.2012

Meh they expect me to get 7 my best has been 6.5 with normal being 6.3 I was getting 7.3 in the prostar I use to drive but this Volvo with Six hundred thousand has not been efficient by any means. But to the OP sometimes the sensors in the tank are calibrated wrong or craps out stupid info. It's a computer it happens.

**anj8488** · 07.02.2012

Originally Posted by transam pete

so fill your tank divide gal into your miles and know for sure your mpg
and try thinking on your own

Can someone explain to me how this is even remotely accurate? Your gauge doesn't give you gallon readings. Terrain, weather and weight, among many other factors play a role in mpg. Someone please enlighten me.

**dorset** · 07.02.2012

start with a full tank

drive until it's low

record the miles you drove

fill to the same level

record the gallons you added

divide miles you drove by gallons you added

mpg

**transam pete** · 07.02.2012

you have to fill your tank to get accurate mpg for THAT trip
averaging a months worth of trips will give you a measurement of mpg
over many trips inclusive of weather conditions, traffic and terrain
so you are correct I can always get 9 mpg empty on an flat highwayat night with no
traffic or wind

**Preacher Man** · 07.02.2012

Originally Posted by anj8488

Can someone explain to me how this is even remotely accurate? Your gauge doesn't give you gallon readings. Terrain, weather and weight, among many other factors play a role in mpg. Someone please enlighten me.

Believe it or not people used to do complicated math without the benefit of computers, calculators or even slide rules. Using the traditional manual method of tracking fuel economy is easy, accurate and a great way to know what is going on with your truck. If you were only getting 3mpg you would know it because you would only get 500 miles before that full tank was down to 1/4 or less. The manual method even works with partial fill ups. All you do is subtract the mileage of your last fill up from your current fill up. That gives you the total miles driven between fill ups. Take that number and divide the gallons you put in the tank, including any partial fill ups. The resulting number gives you your average miles per gallon for that group of miles. Keep track of weather, terrain and weight will show you how all of these factors affect your mpgs, this shows you how much these factors affect your fuel consumption. As I said before, this method showed me I had a problem even though all the computers in my truck said everything was fine.

**Tazz** · 07.03.2012

A good driver will have a pretty educated guess what his mileage is across fill up's. Covering roughly 630-690 a day my fill up should be between 85-95gallons. It's something you'll get a feel for but as mentioned you can track your fuel and mileage across a month or longer to get a pretty good idea what your actual is.

We cross check our qcom lifetime info against monthly fuel settlements to watch for people stealing fuel, and hardware glitches, but ours are pretty accurate to within a few hundredths.I have never seen an instant report after fueling.

**Moriarti** · 07.04.2012

Originally Posted by Tazz

I have never seen an instant report after fueling.

Roehl's QC has a macro that you send in when you've filled up your tanks, which makes it go to comdata (or TCH, I suppose) adds up all the gallons you've added since the last time you sent the "Filled up" macro, then compares the odometer readings, does the math, and sends back the answer. along with what you're supposed to be getting, for that calendar month. With the software problems they're having, the instant report is acting like you're driving down the interstate in 8th gear. "OMG, CALL SOMEONE, YOU DON'T KNOW HOW TO DRIVE!!!"

**Tazz** · 07.04.2012

Thankful we do not have that kind of crud to deal with. Thanks for the response though.

**dude6710** · 07.04.2012

Honestly I drove for roehl, didnt care about mpg. Just hammer down to 63 and make your appointments on time and keep the fm happy. My truck still got 6.3-6.4 Also dont call your FM when you get the message on to call them about MPG, it is what it is.