[BDCCruze]

How are you putting 18 gallons in? Mine clicks off at about 14.5. I can maybe squeeze in another .5 gallons till it at the neck. I've had the low fuel light on and put 50 more miles on before getting gas and it still barely makes it over 15.

 

[BDCCruze]

This guy says covering the vent hole on the fuel nozzle eliminates foaming. I think that's the hole that also tells it when to click off so you have to be careful. In their forums he said if you just do about 1/2 flow you can cover the hole without stopping it from clicking off.

https://www.youtube.com/watch?v=AB082zQ7Das

 

[BDCCruze]

You're going to have to wear plastic gloves on that one ( if you don't want smelly hands , that is)....I carry a box of the nurses-type gloves in the car. Cheap at Costco or SAMs.

The place I fill up has plastic gloves out by the diesel pump, thankfully. I thought I read somewhere that overfilling the tank will cause damage. I wonder if the foaming is considered when they are planning tank capacity and sending unit design.

 

[BDCCruze]

Yeah I tried that “cover-the-hole” technique a few months ago, didn’t work for me at all...made no difference with the foaming.

I’ve been topping my diesel to the rim for a year with no adverse effects whatsoever. My understanding is this should NOT be done with gasoline vehicles but OK for diesels.

Hmm interesting, know what the difference is?

I've replaced the sending unit on more than one gas vehicle and it always seems everything is always submerged anyways. Maybe it has to do with the evap system? Not sure how different that would be on a diesel. Interesting though.

 

[BDCCruze]

It sounds like you might be filling the vapor space.

Yes, that is what is happening. Running the tank that high can damage the evap system. However, it is possible that due to the nature of diesel foaming that GM built the tank to allow fuel to run up over the evap valve and not cause issues.

But for those that want to do this, I would imagine putting 3 gallons of fuel into a fuel jug before filling your car, then use the fuel jug to top off since it won't be foamy once the handle clicks off. That may be an easier way to get it completely full rather than clicking it off for 10 minutes. Or you could just drive home and finish filling up so that people don't stand there wondering what that weirdo at the pump is doing :laugh:

 

[BDCCruze]

Are there any known, documented, and provable reason for a decline in fuel economy? This summer, after a few months of watching, I'm down about 1 MPG average over a full tank.

 

[BDCCruze]

Weather seems to have a lot to do with my fuel economy. Heat and wind can really impact mpg.

I regularly run I-10 between Arizona and California. From about May to October the prevailing winds out of the West can cost me 3-4 mpg heading into CA. On the return trip to AZ if I catch a tailwind it can cancel out most of that loss but not always all.

Then there are those trips where I fight headwinds both ways. Depending on time of day the winds can switch from West to East.

Add to that it’s HOT (less-dense air = decreased efficiency). The turbo helps to negate this impact but it’s still noticeable.

Winter to Spring the winds die off for the most part. It’s on those calm, cool days where the car is most efficient.

Is that how you maintain 55MPG? I think that is just crazy. Is your road pretty flat? I'm lucky to average 44mpg over a tank, sometimes 45.

 

[BDCCruze]

Cruise set on 60 mph, right lane (also a couple years ago the car got ‘lighter’ and there’s a spare tire in the trunk...wink).

However, I did accomplish the first 1,000 mile tank before the ’diet plan’. Same driving pattern combined with a lot of luck (no traffic jams, little wind and very few stops).

I read diet plans don't help much with improved economy anyways.

 

[BDCCruze]

Thing is I could do 60MPH right lane, but our speed limit is 75 and I don't want to be "that guy". When I get passed by tractor-trailers I feel like an idiot.

 

[BDCCruze]

I have a 2015 Diesel Cruze and just had the original battery replaced. Now it seems I cannot hit the 50mpg bar (every 3 miles) in the economy trend graph - except once or twice in 200+ miles. I used to get a solid 10 columns at 50+ mpg...Any thoughts as to why that would change? My driving habits, commute route and routines have not changed. Thanks!

I don't know where you live, but up north, our winter blend fuel normally results in 3-4 MPG loss. You posted during the winter months so it's possible they switched you over? Another thing - did you remember to run the negative lead through the current sensor? It's possible the alternator is working OT if it thinks the battery is not charged.

And just as an update to this thread - I notice at the place I buy fuel you can slowly let off the handle to get it to just trickle out without foaming. Lets you easily squeeze in another gallon without even trying. I suppose hitting 17 to 18 gallons is probably quite possible. I got to 16.5 once from bone dry tank but I left because I wasn't patient enough to do it more.