Until my MINI arrives I have to drive my families Toyota drinks a lot of petrol pick up truck. So to save on gas a bit I have only been filling the tank up half way so that I am not lugging around excess weight on my 11 mile round trip to work. I mentioned this to my friends and one said I should not do that because over time it can harm the fuel pump?!?

First off, will only filling the tank half way up consistently damage the fuel pump? If the answer is yes, please explain to me why that it.

Thanks, DChap

By the way, I don't think that it should damage it at all and cannot understand why he thinks so.

 

While running on half will cause no problems, I've heard that when you run on low fuel, The fuel pump will be clogged with the sludge and crap at the bottom of the fuel tank that has accumulated over the years. Dunno if this is an urban myth but that's the belief.

 

i don't know about the sludge but MINI like BMW cools the fuel pump with the fuel. thus if you run with very little fuel all the time, it can shorten the life of the pump

 

Absolutely avoid running 'out-of-gas' with ANY Fuel Injected engine, can cause costly problems

(When I visited local BMW to ask about MINI {they knew Nothing}, the entrance was blocked by a BMW Demo, out of gas

Drove a few hours to the nearest MINI Dealer and MINI's had their tanks FULL

Never before bought an auto (or aircraft) that included a free tank of fuel

(Aircraft will have tanks full, but it is on your invoice.)

Art

 

1/2 tank of gas will not improve gas mileage. period.

You are much better off being safe than sorry.

 

the reduced weight is probably not going to save you much money. Maybe pennies per tank. You'd be better off managing your own driving habits and how far you punch the throttle.

Half full is not a bad thing, but running the car down close to empty frequently will cause unnecessary wear on your pump.

 

Let's say his current tank holds 13 gallons, making 1/4 of a tank around 4 gallons. Give or take a little. Driving 11 miles with 4 gallons cooling the pump is not gonna make a difference.
Same effect for driving with the reduced wieght. It may make a difference, but you have to drive like that forever to measure it.
Its an 11 mile commute.
Fill the tonka toy up. Run it down low and fill it again. You save 1/2 the increase since last fill up.

That's 1/2 a rabbit. Also known as "splitting hares".

 

I still dont understand, if the tank has gas in it at any level, it should be getting cooled and pumped through. Tank full or not. Thanks for all of the help thus far.

 

I just swapped out the in tank fuel pump in my Grand prix. It was mounted to the top of the tank, with the fuel intake down near the bottom. But the mechanicals were near the top.

 

at roughly 8.3 lbs/gallon not putting in the 6.5 gallons is only saving about 54 lbs. Doesn't sound like its worth the trouble.

You'll save much more altering your driving habits, keeping the tires inflated properly etc.

I applaud the thought, but think you can save mpg other ways more effectively.

 

doesn't quite answer my original question, but that does put such a spin on it that makes complete sense haha.

Thanks

 

I think that what you are looking for is why you shouldn't put half a tank of gas in your tank. The problem is that when you run your gas tank level low you will endanger your Fuel pump, possibly the engine. Gasoline, is not 100 percent clean. What will be present could be rust or dirt from any number of the things that were used to transport the gas to the fuel pump to which you recieved your gas. This rust, or dirt, or "sediment" mixed witht he gasoline will crate a sort of sludge. This sludge is the problem. It will rest on the bottom of your tank. When you run your tank low the sludge will then be stirred, aggitated, due to the motion of the gas in the tank. The lower the level the more the sludge can be moved. That is why gas attendants in say NJ, will put the pump on the lowest speed as to help not aggitate the sludge or sediment. Well when this sludge or sediment is aggitated and moves into your fuel lines to your fuel pump. Well I think you might get the picture from there. Then if it gets through your pump, it can get to the engine.
So in a sense filling up your tank halfway will create a risk because you are bound to run the tank level pretty low at some point which can cause Many problems. So it is basically a risk.