Overfilling (Gas Topping) the 370z

MagmaRed370z · 01-30-2016, 09:38 PM

Are you one of those guys that like to overfill your tank? I sometimes fill it up and put an extra half gallon in there. Am I harming anything? I know some people here that top it all the way full. Just wondering if it's a myth or what.

I tried searching inside the forum and couldn't find a thread about this specifically.

FairladyZ40th · 01-30-2016, 09:45 PM

I don't think it harms in any way just spilled gas and a couple of wasted cents?

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Memphis370Z · 01-30-2016, 10:29 PM

I think the biggest reason not to overfill is that gasoline needs room to expand. If you overfill, I suppose you could mess up the EVAP system by getting liquid gas in to it, instead of gas vapors. At least, that's what I've been told by several mechanics. I just stop filling my tank at the first click.

ramoszx12r · 01-30-2016, 10:49 PM

Do not do it, it will mess up the EVAP and will not pass inspection.
Will cost a lots of $$$ to replace.

DEpointfive0 · 01-30-2016, 11:20 PM

I overfill every car every time

POS VETT · 01-30-2016, 11:35 PM

I fill all the tanks to the brim on all of my cars for about a decade now. After normally filling a tank to the first click or normal container filling, I use a smaller 2-gal container (never through fuel pump nozzle unless the nozzle could go very slowly) to slowly and intermittently pour fuel in until the surface on the filler opening won't sink anymore; it's a very slow process and spilling must be kept to zero to minimum (usually a minor amount from splashing). For the hibernating cars, I may come back days or weeks later to top it off. I never had any problem with fuel vapor recovery system in any cars that I have owned or currently own.

Half a gallon is nothing. The additional amount that's "force-filled" varies from 2-4 gallons depending on the vehicle fuel tank, orientation of the vehicle while being filled, whether the vehicle is rocked, the amount of available fuel on hand, and lastly my patience.

Bad Boy · 01-31-2016, 01:14 AM

I always overfill a little. If not the last LED on my gas meter wont light up.

JC-Nismo · 01-31-2016, 06:20 AM

It's the shoes man, I don't overfill cause I don't want gas on the bottom of my GODDAM SHOES!!!

onzedge · 01-31-2016, 07:49 AM

Quote:

Originally Posted by DEpointfive0

I overfill every car every time

JARblue · 01-31-2016, 08:24 AM

Why would you ever need to do this? I just recently filled up with 18.8 US gallons in the Z with no top off. Considering the capacity of the fuel tank is 19.1 US gallons, another 1/2 gallon would have overflowed

MagmaRed370z · 01-31-2016, 09:45 AM

I know some people when they go to trips they put an extra gallon and a half in the tank. This will give them about an extra 40 miles of distance.

MagmaRed370z · 01-31-2016, 09:46 AM

I always put 0.5 more gallons in the tank. Always have, no idea why.

Sonny10MM · 01-31-2016, 11:53 AM

Since I pay by credit card I don't anymore. Use to just to round it up to the next dollar.

90 ST · 01-31-2016, 12:11 PM

I've always filled my car up as much as I can, usual until I can see gas at the top, never had a problem, with close to 600 tanks of gas on my Z alone.

Fuzzzy · 01-31-2016, 01:32 PM

With the fuel starvation issue of the Z, it makes no sense to me to squeeze in an extra half-gallon just to turn around and fill it before it gets down to a quarter-tank. I have just resigned myself to stopping at a gas station more frequently.

It really isn't a big time-waster--especially compared to any problems that over-filling or running too low might cause.

01-30-2016, 09:38 PM	#1 (permalink)
MagmaRed370z A True Z Fanatic Join Date: Jun 2014 Location: USA Posts: 1,468 Drives: 14' 370z Sport Magma Rep Power: 13	Overfilling (Gas Topping) the 370z Are you one of those guys that like to overfill your tank? I sometimes fill it up and put an extra half gallon in there. Am I harming anything? I know some people here that top it all the way full. Just wondering if it's a myth or what. I tried searching inside the forum and couldn't find a thread about this specifically. __________________ Sold: 2014 Magnetic Black Base. Current: 2014 Magma Red 370z Sport \| ARK Grip Exhaust \| 25mm HR Spacers \| GTR Button \| DRL Mod

01-30-2016, 09:45 PM	#2 (permalink)
FairladyZ40th Enthusiast Member Join Date: Jul 2015 Location: San Diego Posts: 483 Drives: 2010 370z 40th 6MT Rep Power: 61	I don't think it harms in any way just spilled gas and a couple of wasted cents? Sent from my iPhone using Tapatalk MagmaRed370z likes this.

01-30-2016, 10:29 PM	#3 (permalink)
Memphis370Z A True Z Fanatic Join Date: Sep 2014 Location: Memphis Area Posts: 3,117 Drives: '09 MB Rep Power: 124434	I think the biggest reason not to overfill is that gasoline needs room to expand. If you overfill, I suppose you could mess up the EVAP system by getting liquid gas in to it, instead of gas vapors. At least, that's what I've been told by several mechanics. I just stop filling my tank at the first click. UNKNOWN_370, Zbrah, MagmaRed370z and 1 others like this.

01-30-2016, 10:49 PM	#4 (permalink)
ramoszx12r Track Member Join Date: Sep 2015 Location: Carneys point NJ Posts: 665 Drives: 16 370Z Nismo White. Rep Power: 1428	Do not do it, it will mess up the EVAP and will not pass inspection. Will cost a lots of $$$ to replace. MagmaRed370z likes this. __________________ Tony Ramos

01-30-2016, 11:20 PM	#5 (permalink)
DEpointfive0 Premium Member Bitches Join Date: Jan 2012 Location: SoCal Posts: 14,824 Drives: a lot Rep Power: 17151	I overfill every car every time onzedge likes this. __________________ Do YOU want to know what/where I got my username from? ( Click to show/hide ) NSFW due to language:

01-30-2016, 11:35 PM	#6 (permalink)
POS VETT Track Member Join Date: Apr 2015 Location: Columbus OH Posts: 612 Drives: Z34\|C4LT4\|C6Z06\|V25 Rep Power: 3366	I fill all the tanks to the brim on all of my cars for about a decade now. After normally filling a tank to the first click or normal container filling, I use a smaller 2-gal container (never through fuel pump nozzle unless the nozzle could go very slowly) to slowly and intermittently pour fuel in until the surface on the filler opening won't sink anymore; it's a very slow process and spilling must be kept to zero to minimum (usually a minor amount from splashing). For the hibernating cars, I may come back days or weeks later to top it off. I never had any problem with fuel vapor recovery system in any cars that I have owned or currently own. Half a gallon is nothing. The additional amount that's "force-filled" varies from 2-4 gallons depending on the vehicle fuel tank, orientation of the vehicle while being filled, whether the vehicle is rocked, the amount of available fuel on hand, and lastly my patience. MagmaRed370z likes this.

01-31-2016, 01:14 AM	#7 (permalink)
Bad Boy Enthusiast Member Join Date: Aug 2014 Location: Orlando Age: 33 Posts: 295 Drives: 370Z 6SPD Touring Rep Power: 11	I always overfill a little. If not the last LED on my gas meter wont light up. MagmaRed370z likes this.

01-31-2016, 06:20 AM	#8 (permalink)
JC-Nismo A True Z Fanatic Join Date: Sep 2014 Location: Atlanta Posts: 1,244 Drives: 2011 Nismo 370z Rep Power: 13	It's the shoes man, I don't overfill cause I don't want gas on the bottom of my GODDAM SHOES!!! somms, Kzonts and jburch like this. Last edited by JC-Nismo; 01-31-2016 at 08:28 AM.

01-31-2016, 08:24 AM	#10 (permalink)
JARblue A True Z Fanatic Join Date: Mar 2011 Location: Austin, TX Age: 43 Posts: 36,450 Drives: 11 Z34, 98 E36 M3 Rep Power: 2684440	Why would you ever need to do this? I just recently filled up with 18.8 US gallons in the Z with no top off. Considering the capacity of the fuel tank is 19.1 US gallons, another 1/2 gallon would have overflowed __________________ 2011 370Z 6MT Sport Gun Metallic \| ARC \| CJM \| Ecutek \| FI \| Fujimura \| R2C \| SPL \| Stillen \| TWM \| Z1 \| ZSpeed \|

01-31-2016, 09:45 AM	#11 (permalink)
MagmaRed370z A True Z Fanatic Join Date: Jun 2014 Location: USA Posts: 1,468 Drives: 14' 370z Sport Magma Rep Power: 13	I know some people when they go to trips they put an extra gallon and a half in the tank. This will give them about an extra 40 miles of distance. __________________ Sold: 2014 Magnetic Black Base. Current: 2014 Magma Red 370z Sport \| ARK Grip Exhaust \| 25mm HR Spacers \| GTR Button \| DRL Mod

01-31-2016, 09:46 AM	#12 (permalink)
MagmaRed370z A True Z Fanatic Join Date: Jun 2014 Location: USA Posts: 1,468 Drives: 14' 370z Sport Magma Rep Power: 13	I always put 0.5 more gallons in the tank. Always have, no idea why. __________________ Sold: 2014 Magnetic Black Base. Current: 2014 Magma Red 370z Sport \| ARK Grip Exhaust \| 25mm HR Spacers \| GTR Button \| DRL Mod

01-31-2016, 11:53 AM	#13 (permalink)
Sonny10MM Base Member Join Date: Apr 2015 Location: Portsmouth, OH Posts: 18 Drives: None yet Rep Power: 10	Since I pay by credit card I don't anymore. Use to just to round it up to the next dollar.

01-31-2016, 12:11 PM	#14 (permalink)
90 ST A True Z Fanatic Join Date: May 2010 Location: Calgary Posts: 1,861 Drives: 90 and 15 GMC Sierra Rep Power: 421	I've always filled my car up as much as I can, usual until I can see gas at the top, never had a problem, with close to 600 tanks of gas on my Z alone. MagmaRed370z likes this. __________________ Not driving your car to keep it in nice shape, is like not wanting to smash your girlfriend so she stays tight for the next guy.

01-31-2016, 01:32 PM	#15 (permalink)
Fuzzzy Track Member Join Date: Mar 2014 Location: MS Posts: 876 Drives: 2014 370Z 7AT MR Rep Power: 21860	With the fuel starvation issue of the Z, it makes no sense to me to squeeze in an extra half-gallon just to turn around and fill it before it gets down to a quarter-tank. I have just resigned myself to stopping at a gas station more frequently. It really isn't a big time-waster--especially compared to any problems that over-filling or running too low might cause.

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