# Gas topping off



## tamerlane57 (Aug 21, 2006)

I have followed the manual's advice on not topping off the gasoline. I was wondering if this was something that I really need to do. Any suggestions are appreciated.


----------



## pickinfights (Oct 3, 2006)

I think most manuals state that. Insurance reasons.


----------



## 707GTOLS2 (Aug 31, 2005)

We have a float in our gas tanks that indicates the full to empty on the guage
Basically when you top off you throw the float & guage off
so when your guage says empty you really have a couple of gallons left not counting your reserve.
:seeya:


----------



## GTO JUDGE (May 14, 2005)

*I have found that topping off as allowed me to put up to an extra gallon in the tank. It does throw off the calibration on mpg and fuel usage. I noticed if you stop once the fuel pump shuts off the fuel usage is dead on accurate. In my car any how.

Pumping gas when it's cool does seem to fill the tank fuller than when it's done in hotter temps. Topping off does not allow you that much more fuel when pumping in cooler temps. Expansion and contraction....I have noticed this.*


----------



## hardball75006 (Aug 4, 2006)

That reminds me.....I need to go top off my tank. :lol:


----------



## fergyflyer (Apr 18, 2005)

In regards to not overfilling, this deals with expansion and contraction. When the fuel comes out of the ground it is cool. Gas as it heats expands. If you fill the tank completely full and the fuel expands it will push into the filler nozzle. It then goes into the evaporative recovery system and can cause problems for that.


----------



## GRR_RRR (Oct 19, 2006)

It has to do more with emissions than insurance.


----------



## silgoat05 (Jul 1, 2006)

well when i get gas i just put the pump in and when it stops it full is this bad i haven't noticed any problems :cheers


----------



## b_a_betterperson (Feb 16, 2005)

fergyflyer said:


> It then goes into the evaporative recovery system and can cause problems for that.


Yep. A you will win a trip to the dealer for OBD work -- which isn't covered under warranty if there's evidence that you flooded the ERS by overfilling. Won't happen when the pump shuts off -- but if you do stuff like pull the vapor recovery hood back and keep filling, or just do the pump and click thing for a while, you'll eventually be sorry.


----------



## hardball75006 (Aug 4, 2006)

b_a_betterperson said:


> Yep. A you will win a trip to the dealer for OBD work -- which isn't covered under warranty if there's evidence that you flooded the ERS by overfilling. Won't happen when the pump shuts off -- but if you do stuff like pull the vapor recovery hood back and keep filling, or just do the pump and click thing for a while, you'll eventually be sorry.


Evidence?? That would be very hard for a dealership to prove. Unless they had a video tape of the person "topping off", they wouldn't have a leg to stand on in court. If it ever happened to me, I would just claim it was a gas pump malfunction. It would cost the dealer more money in time and labor to "gather evidence", then it would to just fix the problem under warranty and be done with it.


----------



## JMH GTO (Dec 19, 2006)

*This is kinda funny. Well NOT really.*

I topped off my GTO with about three gallons of 93 oct fuel after the dealer I bought the car from had filled it up with crappy 87 oct pee gas. I let the car sit and then the next time I started it up it kept stalling/cutting out off of idle. Maybe there is NO correlation between the two events but it seems that topping of the car really may NOT be a good thing at all. Anyway I have learned MY lesson!:willy:


----------



## putergod (Jan 12, 2006)

it was choking on the 87 octane


----------



## Sabraxas (Oct 29, 2006)

87 Octane?? I thought anything below 91 was like acid in our ULTRA-MEGA-SUPER HIGH PERFORMANCE vehicle. :lol: Well that's my opinion and I'm sticking to it!


----------



## JMH GTO (Dec 19, 2006)

*Actually the car just needed (wanted) to be driven.*

It is still on its first tank of gas (44 miles on odometer) but when I do start/run/drive the goat (very RARE) it runs fine. Once spring comes I will really run the car and break it in. (Unless it breaks/brakes me first!)


----------

