Bogus fuel mileage reporting. Grrrr.....

dieselfan1 · January 29, 2021

I'm not worried if it's off a little bit. It's not that big of a deal really you guys. I really don't care much about mpg's either. It's a 3 ton piece of steel. If you want good mpg's get a Prius not a truck.

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JimCost2014 · January 29, 2021

I drive a 5000 + pound truck with a 6.2 (376 CI) engine, if my right foot gets a little "heavy" I fully expect crappy fuel economy.

If I drive with a light right foot, I still expect to get "not great" mileage, because it is a big heavy truck, so what is actual, compared to what the truck tells me is kind of a moot point.

Like deiselfan1 eluded too, if every drop of gas and penny makes a big difference in ownership, buy an econobox and rent a truck from U Haul when you need it.

Ravenkeeper · January 29, 2021

On 1/28/2021 at 9:56 AM, belchfire said:

Have any of you noticed that the reported fuel mileage is much higher than reality? I track every drop of fuel my truck burns and my hand calculations are always a fraction of the fuel mileage that the computer in the truck is reporting.

Just for the sake of disclosure, I run 275/70/18 tires and I have used the Rough Country speedometer calibrator and my speed is dead-on with my hand-held GPS, so that's not it.

Have any of you guys noticed that? Does it make you mad

I haven't reset my Trip B since I bought it, it's showing 19.2MPG. I've also been tracking every drop with Fuelly, see below.

22 hours ago, dieselfan1 said:

I'm not worried if it's off a little bit. It's not that big of a deal really you guys. I really don't care much about mpg's either. It's a 3 ton piece of steel. If you want good mpg's get a Prius not a truck.

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Some guys, like me, use their remote start to cool/heat their truck up, before getting in and going anywhere, that will lower your mileage, so you can't use it to see if your truck/vehicle is degrading.

JimCost2014 · January 29, 2021

I have to admit, growing up watching my dad log every single thing in a note pad in the glove box on his vehicles, so I get where the mindset comes from.

Sadly though, in 20 years this post will be complaints about someone's "truck" saying they were getting 250 miles on a charge, and it actually only went 235 miles.

dieselfan1 · January 30, 2021

I have to admit, growing up watching my dad log every single thing in a note pad in the glove box on his vehicles, so I get where the mindset comes from.

Sadly though, in 20 years this post will be complaints about someone's "truck" saying they were getting 250 miles on a charge, and it actually only went 235 miles.

No they are going to be saying when's the next bus because they can't afford the $100,000 sub compact electric commuter car.

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JimCost2014 · January 30, 2021

19 hours ago, dieselfan1 said:

No they are going to be saying when's the next bus because they can't afford the $100,000 sub compact electric commuter car.

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Maybe, but I think a lot has to do with how this whole Pandemic shakes out.

A lot of companies are realizing that they do not need the office space and storefronts like they used too, with everyone working from home now.

Cars/trucks might take a big hit, maybe people just won't need them like we do now, so they may be crazy expensive, or really affordable so manufactures can keep their dealership doors open and plants running.

Who knows at this point, if fewer people are driving, meaning less pollution, do we really need the EV's as bad?

dieselfan1 · January 30, 2021

[quote post="2497508" timestamp="1612037385" name="JimCost2014" userid="144073"

Who knows at this point, if fewer people are driving, meaning less pollution, do we really need the EV's as bad?

No we don't.

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Grumpy Bear · January 31, 2021

On 1/28/2021 at 11:56 AM, belchfire said:

Have any of you noticed that the reported fuel mileage is much higher than reality? I track every drop of fuel my truck burns and my hand calculations are always a fraction of the fuel mileage that the computer in the truck is reporting.

Just for the sake of disclosure, I run 275/70/18 tires and I have used the Rough Country speedometer calibrator and my speed is dead-on with my hand-held GPS, so that's not it.

Have any of you guys noticed that? Does it make you mad?

Mine is 8.3% happy. I hand calculate every tank and have for the 135,000 miles I've owned it. My speedometer is dead on as well. But no, not angry over it. Bemused is what I am. Do not see a valid point to lying about it.

martinto · January 31, 2021

On 1/28/2021 at 12:56 PM, belchfire said:

Have any of you noticed that the reported fuel mileage is much higher than reality? I track every drop of fuel my truck burns and my hand calculations are always a fraction of the fuel mileage that the computer in the truck is reporting.

Just for the sake of disclosure, I run 275/70/18 tires and I have used the Rough Country speedometer calibrator and my speed is dead-on with my hand-held GPS, so that's not it.

Have any of you guys noticed that? Does it make you mad?

If your speaking of manufacturers reported mpg, that’s an optimized result...special formulated fuel and a host of other conditions in establishing the numbers. I worked at both Honda of America in Ohio & BMW Mfg’ing in South Carolina. My actual mileage on my Sierra runs within 10% difference with the vehicle display. The algorithm that does on board calculation has +/- variability, so it’s not likely to be dead on. Running with my 6.2L max tow pkg, so my mpg is what it is.

NWI Denali · February 1, 2021

My DIC reads 8% optimistic consistently.

Grumpy Bear · February 1, 2021

8 hours ago, martinto said:

I worked at both Honda of America in Ohio & BMW Mfg’ing in South Carolina. My actual mileage on my Sierra runs within 10% difference with the vehicle display. The algorithm that does on board calculation has +/- variability, so it’s not likely to be dead on. Running with my 6.2L max tow pkg, so my mpg is what it is.

And what is the useful point of doing this? The ECU is capable of exact measurement and calculation. My OBDII ScanGauge II nails it to a tenth. It gets it's info from the ECU.... What's the grand plan?

martinto · February 1, 2021

On 1/30/2021 at 11:06 PM, Grumpy Bear said:

Mine is 8.3% happy. I hand calculate every tank and have for the 135,000 miles I've owned it. My speedometer is dead on as well. But no, not angry over it. Bemused is what I am. Do not see a valid point to lying about it.

11 hours ago, Grumpy Bear said:

And what is the useful point of doing this? The ECU is capable of exact measurement and calculation. My OBDII ScanGauge II nails it to a tenth. It gets it's info from the ECU.... What's the grand plan?

Hey GB, thanks for sharing your expertise. I'm pleased to learn that after 40+ years in manufacturing critical components for turbine engines, industrial engines, automotive engines and motorcycle engines, that there is no variability in such components. That an allowance for a tolerance band is to deny the "exact measurement & calculation" of an ECU. I now wonder why I've seen failed ECU's under warranty returned for replacement when errors were validated. Not sure what lie I've shared as you've stated above in your 11:06PM post. I also have a tolerance band, sometimes I'm in tolerance and correct, but sometimes I'm out of tolerance and I'm wrong, so my statements may have elements of "error" that can be challenged. I applaud your defense of all things ECU & OBDII; spot on Sir.

Grumpy Bear · February 1, 2021

3 hours ago, martinto said:

Hey GB, thanks for sharing your expertise. I'm pleased to learn that after 40+ years in manufacturing critical components for turbine engines, industrial engines, automotive engines and motorcycle engines, that there is no variability in such components. That an allowance for a tolerance band is to deny the "exact measurement & calculation" of an ECU. I now wonder why I've seen failed ECU's under warranty returned for replacement when errors were validated. Not sure what lie I've shared as you've stated above in your 11:06PM post. I also have a tolerance band, sometimes I'm in tolerance and correct, but sometimes I'm out of tolerance and I'm wrong, so my statements may have elements of "error" that can be challenged. I applaud your defense of all things ECU & OBDII; spot on Sir.

Lets try this again. My question is in no way shape nor from a statement about you. I'm not even sure why you would think so. But..it is your observation so please. Let me attempt to be clearer.

It is the DIC that is telling the lie......If it can be 8.3% optimistic +/- 0.3% it can also be 0.3% +/- of perfect. Ergo...what advantage does GENERAL MOTORS see in 'instructing' the DIC to lie?

Apologies..my comments were not intended for you but for the device.

martinto · February 1, 2021

3 hours ago, martinto said:

Mine is 8.3% happy. I hand calculate every tank and have for the 135,000 miles I've owned it. My speedometer is dead on as well. But no, not angry over it. Bemused is what I am. Do not see a valid point to lying about it.

GB, sorry Sir. I thought you were making a statement about me with your post reply to my 1st post. I get it now.

Grumpy Bear · February 1, 2021

1 hour ago, martinto said:

GB, sorry Sir. I thought you were making a statement about me with your post reply to my 1st post. I get it now.

No problem. That said, any thoughts on:

1 hour ago, Grumpy Bear said:

It is the DIC that is telling the lie......If it can be 8.3% optimistic +/- 0.3% it can also be 0.3% +/- of perfect. Ergo...what advantage does GENERAL MOTORS see in 'instructing' the DIC to lie?

?????????????????