VW experts....mod opinions

So I picked up a 2011 Jetta 2.5 five banger with a 5 speed manual. First 2 tanks have got me just a hair under 35 mpg. My only issue is that the thing is muffled so well I find myself buzzing along at 70 in 4th gear for a few minutes. If I were to put a different exhaust or even just change the muffler to give it a little bit of exhaust note could I expect any change in mileage? Would an intake kit do any good? I'd love to be able to sneak up on 40 mpg, if it's do-able.

Intake and exhaust wont net you 5mpg - they will only make you look 15.

Most likely, any potential increase in mileage you may see would most likely diminish as you'll push the car harder here and there listening to the exhaust/intake noises.

LOL @ putting a muffler on cause you forget to shift.

Seriously.....it's so quite there is zero exhaust/engine noise you can hear over the wind and road noise. If I'm pre occupied and downshift for slowing traffic I find myself forgetting to get back into 5th.

Never have that problem driving the wifes car....08 Mustang Bullitt.

I'm not talking boy racer civic fart can exhaust, maybe just a tame little muffler for just a tiny bit of exhaust note.

I find it amusing a brand new car only gets 3 MPG more than cars got 50 years ago... With no overdrive.

I'm not VW expert but the concepts are the same for all engines. For more MPG you can take a few approaches. Not sure what kind of exhaust is on it but start with a good flowing header, eliminate catalytic converter or replace with a higher flow one, stick with a quiet but good flowing muffler (for your application any old long case turbo muffler will be slightly louder than stock but still very quiet).

As for intake, I would be surprised if anyone makes intake manifolds for those engines, though you seem to indicate they do. Any offerings will likely hurt MPG as factory intakes are typically pretty good for lower RPM torque at stock displacement. Wasted money I think, without knowing specifics.

Ideally you should be at least port matching intake and exhaust ports if changing intake manifold or header. Not sure on VW port design but there is probably some efficiency to be had with working the short turn and bowls, as there are on most as cast factory heads. Upping the compression to run 91+ octane will also help MPG. Polish the chambers for added detonation resistance and if it has a quench pad in the chamber consider adding Singh grooves for even more detonation resistance. Compression is key to getting excellent MPG.

If you go to that extent you should be making more lower RPM torque and can probably change gearing to drop a few hundred RPM at highway cruise. No reason a modern econobox like that should be getting 45+ MPG.

Alternatively, accept that you bought a new car and it is what it is. Remind yourself to shift and you're golden.

Yeah an intake and exhast would maybe get you 5,mabye... intake would probably be the best thing with giving 1 to 2 mpg. But that's only if the intake you have now is unefficient. same with the exhaust. If you are going to just change the muffler it would have to be straight thought design, I don't think you would see much of a difference if you had anything different than straight though. But I don't really think its worth it. I would try to make your car lighter and see if that works. If you feel comfortable taking out the spare,jack, seats, not having any passengers.

Definitely not going to get you an improvement in economy. That stuff is so important to the manufacturers that there is a lot of R&D put into it. It probably won't net you any real power either unless you change the tune with an intake and exhaust. Any improvement in power would likely be offset by a loss of torque.

You could get a bit of engine sound out of it if that's what you're looking for.

As for shifting, I'm sure you'll get used to it. Our Audi was the same way when my wife went to it from her Porsche. I would look over and she'd be cruising in 4th or 5th on the freeway. After a while that was no longer the case.

I'm planning on doing an exhaust and tuning on the Audi now that I'm driving it. It's a turbo, so I'm expecting fair gains. Normally aspirated motors are almost impossible to get much from these days. The volumetric effficiency of motors is all but tapped out.

As for economy... There's a fair reason why you aren't getting better economy now than you were years ago. For one, the cars are much larger. They're also heavier. It's for good reason: car's are much safer and more comfortable. Drive an old car for a while and tell me you don't miss the creature comforts. It would be nice to find a compromise in there somewhere. There is easily the technology to get gas cars into the 40mpg range. The new 328i BMW gets 34 highway. I think that's pretty impressive for a car that size and weight with performance that would blow away even super cars from 40 years ago.