Mileage remaining after fuel tank refill - Chevy Traverse

[IndianaMark]

How do cars, specifically the Chevy Traverse, calculate the miles remaining after refilling the tank. (NOT after the low fuel light comes on). Mine will vary from 350-550 miles. The tank holds 19.2 gallons. 18 mpg would be 345 miles. 27 mpg would be 518 miles. Does it use the average mpg at the fillup time? It doesn't magically know if I'll be City or highway driving in the future. I don't know how it can be reliable unless I could enter what I think my mpg would be. Just thinking. I'm looking for a someone with a technical knowledge or educated guess. Thanks for your brain power.

 

[rstcso]

Welcome, Mark. Where are you from?

My experience has been the calculated miles on a fill-up is based on the previous average mpg which was based on the style of driving during the last tank. Once you've driven some on the new tank, the mpg are being recalculated and the remaining miles are adjusted. I really notice this when driving around town, then taking a trip.

 

[IndianaMark]

Indiana. Thanks for your input. I'm guessing the same. It really makes that metric kind of unreliable on several levels. I'll watch the averages at next fill up and see. I'd like to get more input from someone who has knowledge of the algorithm.

 

[TmanP]

Some GMs (my old Lacrosse, for one) base this on a floating average MPG (which seemed to be somewhere in the rough ballpark of a hundred miles or so). That had the funny effect of the distance to empty rising significantly when leaving town for a highway trip with a full tank. If I'd mostly driven around town recently, and filled up on my way out of town, it'd display something like 300 miles, and would climb to somewhere around 450 miles, while in the first bit of the trip, then begin dropping from there after a while.

The Toyotas I've driven differ in a couple ways. First, they never increase other than when filling up with fuel. Second, they tend to drop at a rate of a mile or two per mile driven, pretty consistently (far less volatile than the GM system, which bounces around quite a bit). They also seem much less sensitive to idling (which impacts the GM algorithm far more). From what I can tell, they are based on a floating average too, but a much longer time horizon (perhaps 1000 miles or so, I think). My Camry will display around 500 miles when filling up if the past few tanks have been highway, and more like 375-425 if they've been mostly city.

 

[FreedomOne]

Changed the transfer case and dct gear fluid in the 23 Hyundai Santa Fe. Valvoline SynPower 75w90 for the transfer case and Amsoil DCT for the trans.

 

[4WD]

Our Tahoe only varies about 20 miles in estimation when we fill up - albeit the ratio of town to highway is likely very similar …

 

[repairman54]

In my Traverse and Silverado when going from a in town tank of gas to a highway run you will see miles remaining not count down for many miles as it recalculates after a fill up as previously said.
And just the opposite when going from highway tank of gas to driving around town then miles remaining will drop fast.
Don't depend on miles remaining readouts to get you through Death Valley, E doesn't mean enough.

 

[Smoky14]

IMO one of the most useless bits of information a modern car displays.
Smoky

 

[ATex7239]

GM has the worst mileage until empty estimation of any vehicle brand I have ever driven. Even steady state driving down the highway it cannot seem to get it right.

 

[gfh77665]

Most recalculate as you drive. I really don't care what it says when its full, 3/4, or half. I only start watching it at 1/4. I closely watch it at 1/8. When the "low fuel" light comes on at 50 miles to go, I gas up. Works perfect for me.

 

[Donald]

So my similar question is how are they calculating the average. Some boats have an actual flowmeter but I doubt cars or trucks have one.

So are they calculating the number of seconds the injectors are spraying out fuel in a given time period and knowing the amount of fuel an injector puts out per second they can calculate the flow of fuel into the engine and they know the vehicle speed and can then calculate average MPG.

 

[John105]

The vehicle cannot predict the future. Are you going to get on the highway, or be stuck in traffic, for the remaining fuel? No different than when you go into a casino, and the roulette wheel has some sort of display showing what previous spins were. Why not just ignore range? Imho maybe the reason for it is to encourage someone to refuel. We had a Toyota Sienna rental where once it got to 10, even I felt anxious. But I drove another 90 miles based on my own calculations and knowing it was gonna to be all highway.

 

[John105]

So my similar question is how are they calculating the average. Some boats have an actual flowmeter but I doubt cars or trucks have one.

So are they calculating the number of seconds the injectors are spraying out fuel in a given time period and knowing the amount of fuel an injector puts out per second they can calculate the flow of fuel into the engine and they know the vehicle speed and can then calculate average MPG.

Are you asking how they are calculating consumption, or average? Average is simply distance traveled divided by fuel consumed.

I don’t know about our upcoming GM, but out 2011 Enclave was always showing way more fuel consumed than in reality. My buddy said same with his 2008 Navigator. My 2007 335 is within 0.1 mpg, and 2006 LS430 within. 0.3 mpg.

 

[fdcg27]

This function seems to work pretty well on the HAH.
Miles remaining does decline more rapidly under higher consumption use and the forecast seems pretty accurate.
As someone noted above about their Toyota, miles remaining never increases. It merely declines more slowly under conditions of low consumption.
Baseline at fillup does seem to reflect recent fuel economy.
I trust it enough that I once ran it down to 34 miles remaining.

 

[John105]

GM has the worst mileage until empty estimation of any vehicle brand I have ever driven. Even steady state driving down the highway it cannot seem to get it right.

Well on our 2011 Enclave the consumption was always north of what was actually consumed, so everything is thrown off by that. A Traverse at least in 2011 was the same vehicle. OP’s vehicle holding 19.2 tells me it’s not the same vehicle as ours had a 22 gal tank. Maybe that’s the new 4 cyl one

 

[k1xv]

I suspect they look at your rate of fuel consumption over the last 50-100 miles, and apply that to the fuel remaining in the fuel tank to come up with an estimate of your remaining fuel range. So it is based on how you were driving the car in the recent past. There is no way for them to know how you are going to drive the car in the future, burning up the gas now in the tank. Unless they had a time machine to figure that out.

 

[rstcso]

When the "low fuel" light comes on at 50 miles to go, I gas up. Works perfect for me.

Not the best strategy for the longevity of your fuel pump, as they use fuel for cooling.

 

[ATex7239]

Not the best strategy for the longevity of your fuel pump, as they use fuel for cooling.

If this was an issue I would’ve burned through gobs of fuel pumps by now. Haven’t lost one yet. I gas up when it’s convenient for me and sometimes that’s after the fuel light comes on.

 

[Donald]

Not the best strategy for the longevity of your fuel pump, as they use fuel for cooling.

Yes, but fuel going through the pump not the pump sitting in fuel is what cools the pump.

Although old GM vehicles at the age of TBI would have the fuel pump fail if you looked at it wrong. A Camry of same age, you could run out out fuel every day and never fail.

 

[2009Caraman]

Some GMs (my old Lacrosse, for one) base this on a floating average MPG (which seemed to be somewhere in the rough ballpark of a hundred miles or so). That had the funny effect of the distance to empty rising significantly when leaving town for a highway trip with a full tank. If I'd mostly driven around town recently, and filled up on my way out of town, it'd display something like 300 miles, and would climb to somewhere around 450 miles, while in the first bit of the trip, then begin dropping from there after a while.

The Toyotas I've driven differ in a couple ways. First, they never increase other than when filling up with fuel. Second, they tend to drop at a rate of a mile or two per mile driven, pretty consistently (far less volatile than the GM system, which bounces around quite a bit). They also seem much less sensitive to idling (which impacts the GM algorithm far more). From what I can tell, they are based on a floating average too, but a much longer time horizon (perhaps 1000 miles or so, I think). My Camry will display around 500 miles when filling up if the past few tanks have been highway, and more like 375-425 if they've been mostly city.

Toyota distance to empty doesnt offer any more info than you get looking at the gas gauge.

The only thing people should know is that when a newer Toyota says 0km remaining you will still have about 2 gallons as a reserve.