Dreaded "30 Mile" Gas Range...

[CBLW]

So, the Owner's Manual clearly stipulates that once your on board computer indicates that the car has 30 miles (or less) of gas left in the tank, you should fill up or risk engine damage.

Fine, as a general principle, I can get on board with that. But here's the thing: I live in the city, drive in heavy traffic, and MOSTLY just drive my car back and forth to work. Often times, I get that damn 30 mile range fuel warning when there is absolutely NOTHING that I can do about it anyway. I try to get to a station as quickly as I can to fill up, but honestly, it feels kind of silly that I need to do so.

I know that owning a BMW is an investment, and that it makes absolutely ZERO sense to skimp on gas and engine care, but let's face it people: the economy is crap, and it's PAINFUL to not get to fully utilize what we all know to really be more like another 40 to 50 miles of driving per tank before ACTUALLY needing to fill up.

So my question is, in all honestly, can someone (preferably a non-engine enthusiast/racer/car nut) please just tell me whether or not I'm ACTUALLY damaging my engine by just continuing to drive down city streets when I drop below a 30 mile range? It feels like such a waste of money to have to keep on filling up the tank at that mark, if it's for no real reason at all...

Much thanks!


P.S. Remember, I love my car, and wish no harm to EVER come to it, but I'm also nothing more than a casual driver.

[123D-M]

I have no idea how a low tank level can cause engine damage?? There doesn't seem to be any correlation. Are they worried that the bottom of your tank is going to be full of rubbish that might get sucked up? Hopefully the quality of petrol that is available in the US means you won't have a tank half full of garden waste. I regularly drive my car way past the empty indicator, even past zero on the trip computer as I know it has a good 60km buffer built into it.

[CBLW]

lol I know!! That's what I'm saying dude. It's ridiculous, seems totally impractical, and completely unnecessary. I'm not denying that maybe if you RACE your car or something, then it would be best to have your engine resemble that of a Ferrari's, but otherwise, I mean, I'm just driving down the streets of DC for God sakes!

[syenisch]

I know on older cars you're not supposed to do that because sediments settle on the bottom of the tank that you don't want to suck up. Maybe they're just trying to develop good habits while the car is new.

[jkp1187]

It isn't so much the 30 mile range, so much as the fact that when the fuel level is low, the gauges may not be 100% accurate. And constantly running your tank to empty or near empty can be bad for the fuel pump. (To say nothing of the chance you might get stranded because you ran the tank dry).


Just fill up when it's 1/4 tank, and you'll save yourself a lot of hassles.

[123D-M]

I think what the OP wants is just reassurance that the car isn't going to disintegrate into a ball of flames if they occasionally let it get really empty. I think you should feel absolutely fine about it. As stated above, make a habit of filling up before it is empty but don't stress and go out of your way to find a petrol station just because the warning has come on. Just fill at the next one on your route. I'm sure there are plenty of petrol stations in the US

[TunedM2C]

I always run it down to 10 miles or so before filling up. I've done it with all my cars in the past too.

[pit1]

Agreed, "damage" is directed toward the dirt and grime that is inevitably sitting at the bottom of your tank. That's what fuel filters are for, if you make a habit of running low, consider replacing the fuel filter more frequently.

I sit the same DC traffic, I try to fill up once I'm below half, grandfather's old rule. Also some believe there is increased evaporation below half-tank.

[CBLW]

pit1, isn't replacing the fuel filter something that BMW will do for me at the appropriate time anyway? Or is that a service that I'd need to specifically seek out on my own? Thanks.

[bdardashti]

As 123D-M stated, generally car manufacturers suggest that you not run on an empty gas tank, because of the sediments that CAN be in the tank and COULD POTENTIALLY get sucked in. However, these are usually guidelines, and I don't think we need to worry about them too much in the US/Canada/Europe/Aus or anywhere else with good fuel. Plus, I THINK if you run premium fuel (which you should be especially because of the turbo), you should have even less of a risk since the fuel is cleaner? I'm not too sure on my last statement, so someone correct me if I'm wrong.

[me1.0]

I am no expert, but I believe the problem is more for the fuel pump. If the pump is starved of fuel, the pump can wear faster. When the tank gets low, the fuel can sometimes slosh. I also think that fuel actually cools the pump and if it over heats that can also lead to faster wear.

Feel free to correct me if I am wrong.

[imported_mega]

the fuel cools the pump, it's suspended with a pickup below it

when the fuel tank is low, the pump is above the fuel and not cooled nearly as good

I try to never go below 100 mile range, that's just over 1/4 tank

[CBLW]

How would I even know if I NEEDED a new fuel filter?

[jkp1187]

Originally Posted by 123D-M

I think what the OP wants is just reassurance that the car isn't going to disintegrate into a ball of flames if they occasionally let it get really empty.

Nope, it sure won't disintegrate.

In fact, it won't even start. You're not going anywhere until you replace that busted fuel pump!



And as for the fuel filter, it should be changed on a regular basis, just like your air filter. Check your owner's manual for service interval.

[imported_mega]

Originally Posted by CBLW

How would I even know if I NEEDED a new fuel filter?

you wont yet, they last a long time, unless someone put dirt in your fuel tank

on older cars they will plug with rust from the tank, even my 1974 2002's filter looked good still

[imported_mega]

Originally Posted by jkp1187

And as for the fuel filter, it should be changed on a regular basis, just like your air filter. Check your owner's manual for service interval.

it's not part of level 1 or 2 last I checked, they last a really long time

[CBLW]

jkp1187, right on. So shouldn't I just COUNT on BMW to take care of that at the appropriate time? One of the reasons that I bought this car was for the 4 years of free service...

[My135]

I've just run my car with less than 10 miles range for about another 10 miles with no harm. Surprisingly, the remaining range was bouncing between 9-12 miles and it never went down to zero. Also, I've noticed on my other car, even the displayed range went down to zero, I think the car was still running with the reserved fuel which can be another 1-1.5 gallans left in the tank.

[jkp1187]

Originally Posted by CBLW

jkp1187, right on. So shouldn't I just COUNT on BMW to take care of that at the appropriate time? One of the reasons that I bought this car was for the 4 years of free service...

Probably, if the interval is within 4 years. Might not be, though. IF you're leasing, the point is moot. If you own, you might have to pay for that out of pocket.

Put it this way: I have an 8 year old car with over 100,000 miles on it, and to my knowledge, the fuel filter's been changed once. Still, check to see what BMW recommends for the real deal.

Of course, changing it earlier than recommended won't hurt.

[Duckw]

The OP seems to think it's somehow wasteful to fill the tank before he ACTUALLY needs to. Surely he won't burn any more gas overall if he fills it sooner. +1 on fill at about 1/4, spare the fuel pump, avoid garbage at the bottom of the tank, and never have that 30-mile panic.

[imported_mega]

I hope not, it's 180 $

assuming it's the same as a 335i, realoem does not have our 135i's on it yet

16117163295 180.79 $ REPAIR KIT, FUEL FILTER/PRESS. REGULATOR

[KeithLM]

Originally Posted by mega

I try to never go below 100 mile range, that's just over 1/4 tank

I wish I had a 20 gallon tank. That would be nice.

Originally Posted by Duckw

The OP seems to think it's somehow wasteful to fill the tank before he ACTUALLY needs to. Surely he won't burn any more gas overall if he fills it sooner. +1 on fill at about 1/4, spare the fuel pump, avoid garbage at the bottom of the tank, and never have that 30-mile panic.

Perhaps he thinks that when you fill the tank up you are supposed to drain it first so everything that is left is wasted. I'm not sure.

Of course, if the warning comes on and you panic and rush to the nearest gas station you might be wasting money because often gas stations near busier roads have higher prices. I don't worry about it to much. Once the warning comes on, I make it a point to go to the same gas station I almost always use the next time I go by it. No hurry, no worries.