I've heard another reason but I'm not necessarily agreeing with it, just passing along the info I heard which may or may not be true...

It's something along the lines of condensation coming from the air, the air that's inside your tank when it's not full in this case, and yes I realize that even when it's "full" there's gonna be some air the filler tube still, at least.
Theory is that the condensation (water) mixes with your fuel (not good).
If there is any truth to it, I'm sure it'd have to be an extreme case to make it happen. This would mean extreme temperature variations between night and day, perhaps a loose or missing gas cap and very little gas in the tank to make a small amount of water make a difference.
I see you're in Florida so you are obviously in the clear, especially being only 8 days.
No need to even bring up gasoline going bad in this 8 day absence thread.
Tires won't "flat spot" in that amount of time either.
No need to "warm it up" any more than you would otherwise, not even a minute is needed, just don't drive it hard until full operating temperature is reached, as always.

 

What's the true life of the battery to drain while sitting without it being driven? I was told newer cars 5-7 days is enough because so many gadgets are running in the background, Dealership told me same thing, it's totally BS. So you guys are saying car should fire up after 2 weeks of sitting? I am trying to learn how long it takes, my audio guy said new Vettes die in 5 days with like 17 components running while its off so you have to keep a trickle charger on it.

My honda accords I have left for 2-3+ weeks and they fire up just fine, I have a 2008 G37S with full tech package, right now it has no aftermarket audio or any mods hooked up, just my passport 9500ci which only turns on with the car.

Reason I ask all this is because I left my car at a shop to get battery drain fixed but 2 days have gone by and guy said its only gone down .2 V and he said that's normal and I am telling him it eventually will die after 5 days but he says it's normal and than after I get my sound system hooked up I have a optima battery in the rear to power it.

My question is what is reasonable time for a car to keep power so it starts, a week? A month?

And what is the reasonable time if you have a aftermarket audio system hooked up? Even though it turns off when car is shut off

 

I travel a lot for work (usually twice a month for a week at a time) I have never had my car even hesitate to start and I'm still on the original battery from mid '09. Longest I've gone without driving is 3 week and still no problems.

 

On my previous G35 I had it sit for 2 weeks while away in the garage with no problem starting it.
The longest I ever had a vehicle sit was a month when I returned home on leave from Germany. My 66 VW Beedle sat parked on a street in Frankfurt and started right up when I returned. It had a 6v battery in those days.

Telcoman

 

My car sits at the airport 4-6 days at a time every week. It's always fine when I get back.

 

8 days? Maybe 8 months. Its a new car, not a 1968 G37.

 

I just got back from our beach house for a 12 day stint and that G fired right back up. No issues at all. It also did a 6 day stint in late June with no issues. I wouldn't worry in the least.

 

I guess people think new cars are extremely sensitive.

Think about how long cars sit for sale at the lot. They start up fine.

Id say anything more than 3-4 weeks is where i'd at least have a friend start it and drive it to the store or something.

 

That sounds too good to be true, 2 weeks max, 3 maybe.

Dealership cars are usually at least started once a week and they also die too, I've went to many slow dealerships where they had to bring out a jumped, that's not the case with busy dealerships but ya on our cars I am not sure.

Someone else also said 21 days. I am trying to get my car audio system fixed and the guy told me as Long as it starts in a week you food, after that it's normal for the power drain, I wanna know what is right and to tell him it should start after so long.

Right now he put my car on a voltage meter and is check the voltage daily and seeing how much it is dropping, this is with the audio system totally u hooked, just stock car.

I will get you guys numbers and you can tell me if the drain is normal.

He told me corvettes and newer cars die in 5-7 days, so I don't wanna go off his experience, I wanna know what my car did before I did the audio system, how long it keeps juice and still fires up

I noticed it would die in 1 day with audio hooked up, so he has unhooked the audio and checking how long battery keeps a charge stock

 

I have left my car with two amps and a possessor, parked for 3 weeks while I was out of town and it started fine.
Most of my business trips are 7-12 days. When I get back my car starts fine.

The current draw from an audio system when it it off is very low. Milli amps.

I have worked at a Nissan dealer in my younger years. Some cars that don't sell well sit for a few weeks. No one wants a lime green Altima with cloth seats apparently. =).
That car started fine.

 

I went to Greece for a year back in 1996-1997 (military). I left my 1995 Nissan pickup in storage. It was up on blocks, so as to preserve the tires, but it started on the first turn of the key.

I drove that truck for 181,000 miles. 90% of them AFTER I left it in storage.

 

Thanks a lot for your input, so what type of voltage drop should be normal for our G if it say for a few days or weeks? What should I expect out of my car if its stock with brand new battery and the valve TSB Done and what should I expect with a sound system hooked up? The sound system has 2 amps and (2) 10" subs but it shuts off when car is off. Right now we are testing the car itself and how long it keeps juice without any audio system hooked up.

 

Like I want to spend the money so the car has juice even a month later, that's why I got a optima yellow top installed for my sound system in the back

 

I have never measured how much of a voltage loss it was over a weeks time.
I have owned a wide range of cars and have had cars sit for months at a time. Most with amps, a winch, auxillary power, etc.

With a yellow top you should be fine. I would say you could go even longer. That's why deep cycle batteries exist.

 

My G has sat for two weeks wothout a problem.