hondamore

When do you fill up you car with gas? Are you a drive until the warning light comes on and then push it as far as possible person or do you like to top up earlier? I had this discussion with friends the other day and was just curious what most drivers do. In neuronbob's latest pics, he is driving with very little fuel remaining in the tank which reminded me of the topic, so I thought I would start a thread.

Personally, I fill up when the gas gauge gets to the 1/2 tank mark. My friends thought that I was crazy for employing this criteria for refuelling, but my argument is this:
- The primary reason for my liking to keep the tank more than 1/2 full at all time is a "just in case" rationale. Your car needs gas and so having more gas at all time is better than getting stuck with "not enough".
- I live in a northern climate and very cold temperatures are the norm 6 months out of the year. If I ever run into a major traffic jam where I am stuck for a long period, having a full tank to keep the cabin heater pumping out the toasty warm air is, at the very least comforting and, in rare circumstances, could be life saving. I mention this because a couple of years ago there was a snow storm which caused a multi car pile up on a major highway which stranded cars in sub-zero temperatures for over 6 hours. A near full tank of gas certainly came in handy in that rare instance and supports the "keep your tank full just in case" line of thinking.
- While not as obvious, but the same scenario in the heat of the summer could also apply. Having a fully functioning climate control system in really hot weather is essential and having gas in the tank is necessary for that to happen.
- If I start to look for a spot to fill up when the gas gauge reads 1/2 a tank, I'm never caught in the situation where I drive until the warning light comes on in a remote location and then I am in a panic to find a gas station because I don't know when I am going to run out of gas completely.
- This may be an urban legend or old wive's tale, but I recall reading that running modern fuel injection engines completely out of fuel is harmful to the engine. If this is true, filling up when I reach 1/2 tanks, removes that possibility.

- The down side to filling up more frequently seems to primarily revolve around time concerns. I fill up more often, so I am "wasting time" in the eyes of some. I'm a retired old fart, so time is not really an issue for me, but I can see the point. Secondly, some made the point that a full tank adds weight to the car which negatively effects the fuel economy of the car. I agree there is a minor negative effect on fuel economy with a full tank, but, especially with the Sport Hybrid technology, this factor is minimal and likely would be less than 1/10th of a mile per gallon difference.

So, there's my reasons, feel free to share your fill up habits and the rationale behind those habits.

jdpdata

I like to fill-up at 1/2 tank mark. Wife drive until it's on vapor. I hate it, always tell her to stop doing that. She of course could care less what I have to say about her car.
My rationale with filling up early is that sediment toward bottom of gas tank will get sucked into the fuel lines, hopefully fuel filter will catch most of the larger sediments. Also gas evaporates quickly when tank is near empty. At least that's what I read years ago. Not sure if it proven fact or just bunch of rubbish. I also like use Costco gas exclusive. I will drive out of my way just to pump at Costco. Wife of course, don't give a damn which gas she feeds her car. Which ever station is the closest when red warning light turns on for her. Drives me absolutely insane how she abuses her car.

Our RLX-SH gas tank is so small, I barely get 375 miles range out of full tank. So I always tried to keep it full at all times to avoid driving on fumes.

rlx015

Time for re-fueling on my end is when it drops below the last quarter of a tank. Whenever, however, no pressure, no hurry. Been doing that for the last 20 years pretty much...

andysinnh

For me, a 50+ year NH-ite, you learn to keep it above 1/2 tank in the winter largely to reduce the "empty" area which can result in condensation during cold/humid times, which can mean more water build-up in the fuel lines (and ultimately freeze-ups if you're not careful). I think this was more a "thing" when tanks were metal and more apt to have condensation than plastic tanks. But it's a rule of thumb I carried from my dad, and have "tried" to instill it into my sons with their cars. Partially successful... ;-)

mrgold35

I'm usually around 1/4 to 1/3 of a tank when I fill up my MDX hybrid. It also depends on my weekly errands and I will fill up even with 1/2 to 3/4 of a tank if I'm running by Costco or Sams during off hours (still working from home until 2022). The wife drives the RLX hybrid to around 1/8 of a tank or less and she is always running behind to everything to have time to gas up. She ends up taking my MDX and I gas up her RLX.

x Hades Stamps

To avoid damage to the fuel pump (they're often lubricated by the fuel), we try to fill up when it's about 1/4 full. We never drive for a very long time with the warning light on in any of our vehicles.

Triaque

As Hades Stamps said.

The fuel pump is “lubricated” by the fuel. That is true but only becomes detrimental if there is no fuel. What is most important these days for fuel pumps with regards to level in the tank is motor cooling. Once you drop below 1/4 in the tank depending on road slopes, the fuel may not be “bathing” the fuel pump electric motor drive in liquid. The fuel pump motor windings will begin to heat up if the level is sustained below the casing of the pump motor and life expectancy of the motor can be reduced.

This is the primary concern with fuel level on modern vehicles.

mrgold35

The 15 gal fuel tank can be a major downside when traveling with the RLX hybrid. The RLX ran very low on fuel on the hwy at 80 mph in a very stiff +30 mph headwind on a 250 mile road-trip. My MDX hybrid get lower hwy mpgs; but, the extra 4-5 gallons of gas in the 19.4 tank would get me 75-100 extra miles down the road.

hondamore

Thanks to all that responded. I feel like less of an anal retentive, paranoid, worry-wart for filling up at half tank now that I have read others reasons for doing the same.

I agree with concerns about the RLX Sport Hybrid gas tank sizing. I think they had limited space because of the battery and they justified their choice by saying that the improved city fuel economy meant that the car had an equal or greater city driving range as the non-hybrid version. I don't do much highway driving in my RLX as we always take my wife's MDX Sport Hybrid for highway trips, but I am certainly a driver that feels more comfortable on the highway with plenty of available driving range especially when the next gas station could be a hundred or more miles away.

Thanks again.

Triaque

Hondamore:

I regularly get 34 MPG with my 2020 SH SH. I have driven on long trips into the steep grades and snake-like curves of the NC Mountains. I never have had a concern with fuel on long distance trips.

Basically, we all have to maintain awareness of changing conditions in life and try to be prepared the best we can with what we have. Even with our best efforts, ........things happen beyond our control.

DanL07RL

HA!! Why, thank you Per'fessr!! Don't know how I ever survived the last 72 years without that bit o' wisdom!!

Puleeze!!

hondamore

Triaque, I don't think anyone was saying that the highway range of the RLX Sport Hybrid is insufficient, just that relative to the MDX Sport Hybrid or even the PAWS RLX, the highway range is lessened by the smaller gas tank. I too have never been anything but impressed with the mileage that I achieve with my RLX Sport Hybrid, but I would be even more impressed with the highway range if they had been able to shoehorn in a larger gas tank.

x Hades Stamps

Yeah. There's the cooling. Plus, in terms of "lubrication," I prefer to run as little risk to running completely out of fuel as reasonable.

mk5

Southern climate. When light goes on. I’m hardcore, baby.

neuronbob

I generally fill up at 1/8th tank. Occasionally, I am surprised by the fuel light coming on, at which point there's two gallons left. Two gallons is plenty to protect the fuel pumps. I don't depend on the light, though. I think the most I've ever put into the tank, even with the light on, is 13 gallons. I'll be testing highway endurance in two weeks when I drive my Sport Hybrid to Florida. Fingers crossed that the weather stays decent.

mrgold35

The RLX hybrid has plenty of passenger room for 4 adults for a long trip; but, only enough trunk space for two. We had to take the MDX hybrid for our trip the Grand Canyon with 4 adults (1700 miles round-trip). We would have taken the RLX if it was just the wife and I.

neuronbob

I’ll be taking my wife, son, and MIL. Owning a NSX, I am familiar with packing Jenga for long trips. I’ll make it work.

hondamore

I've always wondered how many mothers-in-law would fit in the Sport Hybrid's trunk?

neuronbob

Thankfully, I actually like my MIL, so I’m not finding out on this trip