stew1100

There are folks on this forum that say you should always fill your gas tank before it reaches half way, because the passenger tank empties first. That way your sending unit in the passenger tank wont be exposed to air, and there for won't corrode as fast.
It is also stated that keeping the driver side tank full keeps the fuel pump cooler, and will make it last longer.
My question is, if you always fill up before you are half empty, won't the gas in the driver side gas tank degrade from age?
If the gas in the drivers tank does indeed, not get replenished, It could cause all kinds of problems. Or am I missing something?

07MontyRed

I live in the corrosion capital of the world (Florida) and have routinely taken the car down close to empty for 11 years now ... no issues at all. Your mileage may vary ...

unclecookie

That would sure make going on a long trip a bit of a challenge. I think it's silly. I fill my car up when it gets near empty.

TorchRedFred

This comes up in every forum I've been in. In my opinion, I don't care what anyone says, I run all my cars to almost empty and always have for 25+ years and I never once had a problem with any car. And some of them I have driven to 150k plus miles before I sold them. And every time I use my wife's car, the tank is always empty and still never had a problem.

J3TVETTE

I try to fill up between 1/4 and 1/2. I had a fuel pump failure in an Escalade and it was very costly.

richhoff

I found the following in a prior forum post and believe it to be true. The fuel flows from one tank to the other to keep them even and balanced.

"There's a large cross pipe connecting the two tanks. It is near the tops of the tanks. When you fill up, the driver side tank fills to the level of the cross pipe, then fuel flows through the crossover to the other tank. When the passenger tank fills to a level above the crossover pipe, air pressure rises in the remaining ullage space and causes the fill nozzle to trip off. In other words, both tanks are full when the nozzle trips.

The fuel pump draws from the driver side tank and feeds the fuel injection system. As fuel is pumped from the tank, it is drawn through a venturi pump which transfers fuel from the passenger side tank to replenish the driver side tank. Thus the levels in the two tanks are maintained approximately the same at all times."

I usually run mine down pretty low before filling up. Usually around an 1/8 tank or so.

Torchsport

I've run mine until the low fuel warning comes on. Never had an issue.

C6ToGo

Don't think the left tank can go stale because there is only one fuel pump and it is in the left tank. As fuel is pumped out of left tank, a venturi effect draws fuel from the right tank until it is emptied. It is continuously mixed with the left tank fuel.

IMO don't see need to refill so often. Sulfer in cheap gas is the culprit to the right tank sensor. But I thought the electrical part of the sensor that gets corroded is towards the top. So is already exposed after a couple gallen drop.

Johnathon59

Usually when it gets below 1/4 I fill up, after 4 yrs. no issues

airmed2

This car is designed for the stupid masses, and not as the ultra NASA space vehicle used primarily by those gifted with a smarter noodle than me. After all, it really is just a GM, and it's a simple system. Unless there's something specifically in the manual that says don't ever let it go under half, then I'll categorize this as another Trump fake news story.

stew1100

Thank you all, I usually run mine down to about 1/8 then refill.
I did not think it would hurt anything, but you never know.

NY09C6

I don't fill any car I own until the light comes on or it's on E. I never had a fuel pump issue even with cars around 150k.

AviBen

In 50 years of driving (!), I've almost always let the tank go to 1/4 full or less before filling up. This includes cars I drove for 198,000 miles (a Benz), 170,000 miles (an Olds), and 130,000 miles (a Lincoln, worst piece of crap I ever had). I have NEVER had a problem with the gas tanks or gas lines in any of them. My 2012 GS has over 40,000 miles and I drive it the same way. I do, of course, follow the advice of filling the tank (and putting in an additive) before long-term storage.

Corvette_Ed

My C5 coupe developed fuel sending unit issues because the sending unit was exposed to air and oxidized. It took three years and many, many bottles of Techron to get it clean enough that it started working correctly again. To have it repaired would have cost me well over $1k. I never let my C6 drop below 1/2 tank unless I'm traveling, and then I'm looking for a gas station at 1/4 tank.

CSixDude

If you run a bottle of Chevron Techron through the tank twice a year, you shouldn't ever have a problem with the sending unit.

jmeirhofer

I have made it 18 miles after the low fuel light so far. I am of the fill up when you need to variety. I have have been driving since 1976 and have run out of fuel a number of times before the days of the low fuel light but I have never had a fuel gauge sensor failure. I have a few mechanical pump failures over the years.

I think some of these things you have to take with a grain of salt. Can they happen? Sure. But will they happen to you? Odds are no. Because if the chance was that great of it happening, it would be like the harmonic balancer issue. There would be a ton of aftermarket fixes and dozens of you tube videos.

CloudLS9

Is the second tank smaller? I try to fill up before a quarter tank remaining on my ZR1 as that last quarter seems to go VERY fast. Much faster than the first quarter when full anyways.

Corvette_Ed

This failure was one of the most common gremlins among the C5's, and carried over to the C6's.

JasonAndrew

I'd be curious to what brand of fuel the posters who are having corrosion problems are using.

Corvette_Ed

I used primarily Chevron with my C5, which contains Techron, and in rare instances I used Shell.