khooni

Given that this is not a DD, what are the pros and cons of a larger tank.

The only one i thinking that matters is that I like to run the car on track to a minimum of 1/4 tank so I won't get full cut issues. Think the 55L tank only allows me to run 3 sessions before i need to fill up again.

64 L tank will obviously go further but car will also be heavier at the start of the day.

does it matter? conventional wisdom dictates that bigger is better. anyone else getting a smaller tank and why?

DeerHunter

I see no reason to get the smaller tank except for curb weight bragging rights. If you really care about the last kg, shortfill the tank by 10 liters and you derive the same benefit. Myself, I hate having to leave the track in order to refuel. Between that and the fact that I'll also be taking this car on road trips, spec'ing the larger tank was a given.

acey81

Agreed, you will need the extended range - also on track! I doubt that the smaller tank makes much difference, perhaps if you are already doing AC and Radio delete just to complete the entire weight savings program. Otherwise, stick with the larger tank.

fishing

I kept the small tank. I need breaks on longer road trips, so longer cruising range does not help me. More frequent fill ups means fresher fuel and less condensation. Both better in my situation. 55 liters should give 300 mile range on highway. I need a break by that time.

orthojoe

One annoying thing about the extended range tank is that you fuel gauge is NOT calibrated for it. On the GT3, I can drive 120 miles on the highway, and upon arrival the gauge says I've still got a full tank.

Agree with others, though, unless the above bothers you, there's no real reason not to get it.

gled

The extended range tank is the stock tank in the Cayman.

Alan Smithee

^ that would bug the crap out of me.

Personally I would not opt for a larger tank in a car I don't drive long distances in. For a weekend car that may not see much action in the winter, I'm with fishing - fresher fuel, less condensation - and lower weight.

katmeho

Whoa! Im assuming that at some point it catches up and tells you when you start to run out of fuel right? Like it only starts to go down once it reaches a certain point?

jphughan

There is no downside to the extended fuel tank. It's already been confirmed that it does not affect cargo capacity. Porsche defaults to a smaller tank because curb weight measurement at least in the EU is based on the gas tank being filled to a certain percentage of its capacity, so using a smaller tank allows them to shave a few pounds off the official weight. Otherwise, at the track if the extra weight bothers you, don't fill the tank all the way. It should be pretty easy to figure out how much gas is in the tank based on the needle and knowledge of fuel tank capacity, in which case you can just watch the counter at the gas station to stop fueling at the desired point. I suppose you could argue that the extended tank unavoidably adds some weight due to the extra material of the larger tank itself, but talk about splitting hairs at that point....

I don't understand this logic. Do you always drain your fuel tank in one uninterrupted drive? If not, the smaller tank just means more stops at gas stations per week/month. And even if you do, if you need a break on a long drive sooner than the extended tank would be depleted, then just fill up when you take a break even if the tank isn't empty yet -- it's not a great idea to run a fuel tank close to empty anyway because the fuel pump is in the tank and relies on being submerged in fuel to keep cool. But that way, for times when you drain the tank over a larger number of shorter trips, you'll be able to take more of them before having to stop at the pump.

As for fresher fuel and less condensation, vapor lock hasn't existed on cars for a very long time, and fuel can stay fresh for months. The increased capacity of the extended tank is nowhere near enough to make a meaningful difference with respect to fuel freshness. Assuming you get an average of 15 MPG and fuel only stayed fresh for 2 months, in order to have fuel in the extended tank go bad when if you'd had the standard tank it would have been empty within 2 months, you'd need to average less than 1520 miles per year (~250 miles in 2 months) -- but since it sounds like long trips are a concern for you, I'm going to assume that you'll drive more than that. And if you drove less than 1280 miles per year (~215 miles in 2 months), you'd have fuel going bad in even the standard tank. So you'd have to have mileage that was both extremely low and that fell into an extremely narrow range in order for the extended tank to constitute a downside.

jphughan

Seriously? They couldn't take the effort to calibrate the tank properly, or better yet just design a tank and/or measuring mechanism that automatically adapts to the characteristics of the tank? Add fuel tanks to the items where legendary German engineering doesn't apply, right there with cupholders. That's especially odd considering that as has been pointed out, the extended tank on the GT4 is the standard tank on the regular Cayman.

Doesn't deter me from getting the extended tank though. I'll just pretend I'm getting amazing MPG immediately after fill-ups.

Yes. Reading over the discussion in the GT3 section, consumption of the extra capacity of the extended tank isn't reflected on the needle, but once the amount of fuel in the extended tank drops to the full capacity of the normal tank, the needle starts working as normal. This of course assumes that Porsche hasn't corrected this for the GT4. Here's the relevant GT3 thread: https://rennlist.com/forums/991-gt3/...ervations.html

orthojoe

Yup. Silly, isn't it?

Schmidts Cat

I would get the larger tank. When at the track I never run a full tank anyway... Fill to 1/2 or 3/4 and do a couple sessions, then repeat.

Schmidts Cat

Btw, I've left for thunder hill, 2 hrs north, many times on almost empty... Light on... Gotten there!

Alan Smithee

That's almost exactly what I averaged in my Spyder, and it's replacement has been about the same.

supercup

I am getting the extended range tank. All the race cars come with the larger tanks (GT3 cups), not the smaller tank for the 4S (in the 911 case). No downside to extra gas and if you move up the track ladder to race your GT4 at some point and do an enduro you will be glad you have the extra capacity!

If you arguement is your gas will go bad from sitting - you are not driving your car enough! If it sits for that long you can simply put the gas our and use it in another car. That would hold true regardless of the size of the tank!