On my way to 800, what is max fuel capacity?

[veryhumid]

I have read a number of people saying they fit 16-17 gallons in a A4 Jetta tank. Is this correct? I have been able to fill up near 700 miles, but that is after the light has come on. It will take 14-14.5 about that time. I usually fill up until I can see the fuel (maybe it is mostly foam?) and it clicks off often. I did replace the sender in my tank a while back, is it possible that my gauge is off and my light is coming on before it is really down to reserve? What is reserve, btw? I have done the ventectomy.

Thanks, guys!

 

[greengeeker]

yes, it's very possible your light is coming on at the wrong time....you need to recalibrate it when you install a new sending unit. Reserve is 1.9 gallons. Where is your needle when you fill up?

 

[T_D_I_POWER]

That would be Tank size= d (miles) / mpg

So, if distance travelled is 700 mile and mpg is 45

.: Tank size = 700 / 45 = 15.5 gal.

Your manual should tell you the tank size

 

[veryhumid]

yes, it's very possible your light is coming on at the wrong time....you need to recalibrate it when you install a new sending unit. Reserve is 1.9 gallons. Where is your needle when you fill up?

The needle stays above the full line when I fill up for about 100 miles if I baby it. I'll check my Bently on recalibrating but if you know of any instructions I would love a link. Thanks for letting me know about reserve.

That would be Tank size= d (miles) / mpg

So, if distance travelled is 700 mile and mpg is 45

Therefore Tank size = 700 / 45 = 15.5 gal.

Your manual should tell you the tank size

I think the official tank size is 14.5? However I bought my car as a wreck so I don't have a manual. Thanks for the calculation, I can see from that I may be closer to the 16-17 people are getting.

Also, I think it would be useful to have a post or addition to the FAQ for each fuel tank type that says how much you can squeeze in.

 

[greengeeker]

http://forums.tdiclub.com/showthread.php?t=96139

http://forums.tdiclub.com/showthread.php?t=174576

 

[mrGutWrench]

That would be Tank size= d (miles) / mpg

So, if distance travelled is 700 mile and mpg is 45

.: Tank size = 700 / 45 = 15.5 gal.

Your manual should tell you the tank size

__. The manual only states with the vent in operation. As has been posted here over and over, the actual capacity of an A4 tank is 17 gallons (=/- a tenth or so). Been confirmed many times. That's absolutely full to the filler neck, no foam, with careful venting or ventectomy.

 

[McBrew]

The ventectomy adds to the top of the tank, not the reserve. With your MPG, you should be driving 160+ miles before the needle moves off of full. I'm guessing that you aren't filling up as high as you could because of foaming. As mentioned, 14.5 gallons is the capacity of a non-ventectomied tank. Yours now holds just a tad over 17 gallons. The low fuel light is designed to come on when you have 1.9 gallons left, but it could be out of calibration.

 

[T_D_I_POWER]

__. The manual only states with the vent in operation. As has been posted here over and over, the actual capacity of an A4 tank is 17 gallons (=/- a tenth or so). Been confirmed many times. That's absolutely full to the filler neck, no foam, with careful venting or ventectomy.

I don't get it. I was just helping veryhumid how to figure out the tank capacity, when you don't have a manual, using a mathematical equation given the the mpg and distance travelled. Btw, do you know how to do this?

How many of you guys keep asking the same questions about the type of oils should be used in the TDI engines many times over?


Rev A: Is: mathematical was: mathetical

 

[txpigeon]

My biggest fillup was 17.107 gallons @ 889.1 miles, 51.973 mpg. Light was on, but engine still running. Pucker factor was very high! Best mileage was 900.3 miles on 16.046 gallons, 56.107 mpg, all interstate.

Duane

 

[roadlust]

If you keep squeezing fuel into the tank until it is all fuel and no foam you can get 2 more gal. in it. It takes a while be patient.

If I baby it I can get 200mi before it comes off the full mark, I fill until I see pure diesel standing at the top of the filler neck.

 

[MX45OR]

how long does foam take to dissapate?

 

[velociT]

how long does foam take to dissapate?

While fueling once the pump clicks off?

I would say 15-45 seconds depending on the fuel.

 

[2004STARWARSTDI]

trying for 800

Veryhumid there is a possibility in your quest for 800 in damaging the lift pump in the tank. Lift pumps require fuel to cool them and running low will overheat them and also a possibilty of sucking up dirt into pump! Just my .02 take it or leave it.

 

[Redputter]

Veryhumid there is a possibility in your quest for 800 in damaging the lift pump in the tank. Lift pumps require fuel to cool them and running low will overheat them and also a possibilty of sucking up dirt into pump! Just my .02 take it or leave it.

My issue with the 'if you use the last bit of fuel in the tank you will suck up dirt' argument is that you are sucking from the bottom of the tank, where, ding, the dirt settles all the time. So in fact, unless there is dirt floating on the surface, I don't buy the 'dirt' issue.

On the other hand, there may be something to say for hot fuel. Now, if it is just a VE rotary pump engine, I wouldn't think there would be much heat generated, as the pump pressures are relatively low. As you move to the PD and especially the common rail engines, the higher pump pressures will create more heat in the return fuel. However, unless it is an extremely hot day and all sorts of other factors, I wouldn't be extremely worried, as I'm sure VW tests these engines under hot fuel conditions. Granted, cooler fuel is generally better, but you could do a lot worse for your fuel system, like use biodiesel, jet fuel, or high sulfur diesel....