I'm debating between a 15 and 20 lbs. bottle (NOS). The dimensions are pretty close. 27 x 7 vs. 27.5 x 8, so "packaging" really isn't an issue. Maybe it will still fit in the spare tire well?

Anyways, my question is if there is any performance advantage of running a smaller bottle? I've heard that once a bottle starts getting low on N20, it's harder to use "that last bit" of juice with a bigger bottle since the volume is greater.

Any truth to this?

 

Depends on the efficency of your heater.


I ran 2 heater pads (no stats) on my 15lb bottle in the past.. Now I run a NX automatic heater (single pad). I havent had an opportunity to test the new setup though.


I doubt that the size of the bottle has much correlation to flow directly, but the problem is when nitrous flows it cools down the bottle... cooler = lower pressure = less power. (You can see the difference of flow by doing square root of the ratio of pressures (actual pressure divided by recommended pressure). )


When a giant bottle gets low on juice, it is a PITA to heat.. It's common practice of only using 70% of a bottle before refill. Otherwise it's VERY difficult to get to proper operating pressure.


In short, I rec. a 10lb bottle... a 15 tops..

I run a 15lb in my GTA, only because I didn't pay for it.


As far as fittting a 20lb bottle in the spare tire well... Isn't going to happen. Here's a 15lb bottle in my thirdgen's spare well:



(same size area as 4th gen)