Fuel Guage vs. Range Meter - miles to go

[johnrieder]

Can anyone offer any information regarding fuel guage accuracy?

[REC]

I haven't had that many fill ups yet (one of the primary benefits of a hybrid!), but so far the car fuel guage is pretty close to the amount the car takes at the pump.

 

Of course, we'll have a better idea after 3 or 4 months with the car.

[ptjones]

After three fillups it seems tobe very close.

[MSmith1915]

I filled up the other day with the tank approaching empty.  The fuel pump symbol had turned yellow on the way to the gas station.  Just before I got there (about 15 miles away) the fuel symbol color changed to red and the the fuel low warning popped up on the information display.  Total gallons pumped:  12.127.  And that is for a 13.5 gallon tank.  My wife did most of the driving on this tank of gas and she averaged about 37 MPG.  To be fair to my lovely wife, the information display showed 39.3 mpg.  Total miles on this tank 447 and it was two weeks between fill ups.  Keep in mind, she doesn't know anything about hypermiling, ICE, regen braking, coasting.  She just mashes the gas pedal and goes.  I'm getting close to 8 mpg more on this tank of gas.

[stranger267]

It is pretty accurate except 'miles yoiu can still drive on tank' which has some hidden reserve (I think, maybe about 5 - 10 miles). I reset the trip 1 when fill in the tank, then drive, and then compare trip report and gas station reading - both show me '12.1 g used  / 12.1 g purchased' (trip reports 12.1 and I added exactly 12.1 g of gas).

 

We used to have a 'yellow' sign about 40 - 50 miles before 'empty'; CMAX show it about 30 - 40 miles before empty - little too late, but acceptable.

[SBGrad]

The "xx miles to E" seems WAY conservative to me, as is the red/yellow triggers. I get the yellow warning when MyView reads ~75 miles to E, the red warning comes on ~40 miles to E. The thing is, Trip 1 says I have burned less than 12 gallons! WHy does it go red when I have 1.5 gallons left?! Why does it read < 30 to E when I've got 1.5 gallons left? Ford is being conservative but it makes me go crazy not knowing how far I can/should go before the tank is actually empty. It's something I'll be raising with the engineers at the owners event in a couple weeks.

[Jus-A-CMax]

I had more range with less red bar in my 600 mile/tank run last week. It probably factor in your MPG. Plus, I rather it go conservative else you hitch a ride on the back of a tow truck ala http://fordcmaxhybridforum.com/index.php?/topic/1062-its-days-like-this-you-wish-you-had-a-gas-engine/

[roninsd]

There's always a way to test just how far you can go ... just make sure to carry a gas can, or your AAA card.  ;)

[JAZ]

Perhaps not so much of a concern on a new (and presumably clean) fuel tank, but from Bankrate.com:

 

 

Little driving tics and quirks you've had for years could be hurting your car and costing you some serious cash.

Here's a closer look at some common driving no-nos and the damage they can do to your car and your wallet.

Driving on empty
Do you pride yourself on getting every last drop of gas out of your gas tank before filling up? Cut it out.

Sediment from gasoline settles at the bottom of every gas tank. When you let your gas level run low, you force your car to use the dirtiest gas in its tank for fuel.

The lower your car's gas level sinks, the more the dirt gets stirred up from the bottom of the tank. Drive on a near-empty tank and you risk this dirt getting into your car's fuel line and even into the engine. There's a good chance your car's fuel filter won't be able to catch all of it, especially if you drive with a barely filled gas tank on a regular basis.

"You're going to pull the heaviest sediment into the fuel line," says Karl Brauer, editor-in-chief at Edmunds.com. "If it gets all the way to the engine, it could scar or damage internal parts of the engine."

If this happens, you're putting extra strain on the engine. And you'll need to flush the entire fuel system if it clogs up with dirt.

"You're talking a minimum of a couple of hundred dollars if it really jams up the system," Brauer says.

At the very least, you'll need to replace your car's fuel filter more often. That will run you about $100. And if sediment deposits or sludge form on your fuel injectors, you won't like the way your car drives.

"The car will run funny," says Tony Molla, a spokesman for the National Institute of Automotive Service Excellence. "It will feel like the car needs a tune-up."

The best advice? Never let your gas level dip too low.

"It's a good idea to keep your tank half full," Molla says

.http://www.bankrate.com/finance/auto/bad-driving-habits-can-wreck-your-wallet-1.aspx

[PWBarrett]

There may be a little bit of truth to that, but never letting it get below half full is ridiculous.

The fuel is pulled from the lowest point in the tank anyway, then goes through the fuel filter.

Particles have to be microscopic to make it through the filter.

Yeah if you always try to practically coast into the gas station on fumes you might clog the filter a little sooner.

With the exception of one car that shall remain nameless, in decades of driving I think I've only had one fuel filter changed.

[TxWally]

My folks had a 71 dodge dart with a dent in the tank. You never wanted to let that car go below a quarter tank.  :nonono:

 

But constantly keeping your tank more than half full?  

Sound a bit optimistic. ;)  

 

Besides would you constantly keep an extra 40 lbs of luggage in the trunk if you do't need it? 

[JulieB]

I suppose it depends on your circumstances.Someone who's on call for emergencies (with a volunteer Fire Department, for example) probably doesn't want to be caught low on gas. Filling up at half a tank ensures that there's enough gas in the tank to answer a call. 

 

I know people who like to fill up at the halfway point because it costs less. Yeah, yeah. I know. But think about a senior who doesn't drive much and is on a fixed income. If that's how you budget, then it makes sense. 

 

I plead guilty to filling up at half a tank under certain circumstances, but it's generally when I'm about to hit the road. I like to have a full tank when I start a trip.

[Tdefny]

My fillups have been dictated by convenience rather than necessity so far. Predicted range should be a better metric if you like to run the tank down, as I do, because most fuel gauges are not linear and you could get caught short without a reliable estimate.

 

I have a friend who used to have a 280Z that had a second gauge that accurately read out the last quarter of the tank.

Edited February 3, 2013 by Tdefny

[plus 3 golfer]

Ford acknowledges an "empty reserve" which is included in the advertised capacity = indicated capacity + empty reserve capacity. So, there is a reserve when the fuel gauge and miles to empty shows zero. Ford says don't depend on the empty reserve because

It can vary.

 

I don't understand the obsession with squeezing the last drop of fuel from the tank. That's likely why the MTE is conservative. Why have irate customers when they run out of fuel with 1 MTE.

[TxWally]

OK, last Friday I decided to push it. 

The Cmax said i had 54 miles worth of gas in it on my Friday drive home from work (39 miles). A 15 mile difference.

By the time I got to the gas station it was down to 6, and I did't do anything different than my usual home commute (~41 mpg).

 

BTW, I'm usually the guy who fills up at a quarter. Strange driving so long with a yellow then red gas pump on the dash.

[SBGrad]

OK, last Friday I decided to push it. 

The Cmax said i had 54 miles worth of gas in it on my Friday drive home from work (39 miles). A 15 mile difference.

By the time I got to the gas station it was down to 6, and I did't do anything different than my usual home commute (~41 mpg).

 

BTW, I'm usually the guy who fills up at a quarter. Strange driving so long with a yellow then red gas pump on the dash.

 

So, when you finally filled it, how many gallons went in?

 

I never fill it until after the gauge goes red, and I still haven't been able to put 12 gallons in-- meaning I have at least 1.5 gallons left in the tank.  IIRC, the last time the gauge was red, < 20 miles to E, and I could only put 11.75 gallons in.

[Marc Smith]

ON my prius  the gas guage had ten lighted pips.  Prius tank was 11.9 gallons.  once the gauge got down to a single pip  it would start flashing, which meant  you'd have about 2 gallons of gas left. (or nearly 100 miles until dry)

 

so Nice that the c-max has yellow, then red warning...  and it seems that if you had reset the trip meter when fueling  the amount fuel used is pretty accurate with what folks have had to put in.

 

The prius had  a problem with "topping off"  if you topped off too much  you end up filling up the  charcoal evap canister....  Any worries about this same problem with the c-max... 

 

Still kind of wierded out by the  capless gas tank...

 

Currently a bit more than half way through my first tank.. 8.06 gallons used  358 miles  which will put me close to a 600 mile tank...not bad for my first tank...