2011/2012 Jetta TDI Build
 

Hi everyone,

Dad just bought a 2011 Jetta TDI, I'm going to be getting a 2012 Jetta TDI and I'm hoping to squeeze out a little more MPG than before. My goals are to keep a stock/sportier looking car (so looks are a big deal), but not exactly concerned about high performance (still want to do normal highway driving at 3 over, which isn't exactly MPG friendly and be able to speed up easily to 80 to pass if needed). Below are my plans, not all happening at once, but hopefully eventually.

2011/2012 Jetta TDI build

• I am considering installing video cameras (if legal in my area) to substitute as mirrors.
• Shaved door handles. Maybe even a sort of pop up thing like new fuel tank accesses (may be too complex).
• Slight lip spoiler (since I've heard these actually increase MPG on the 2011 Jetta)
• Lowered suspension with a body and side skirts to block out air from the underside of the car with a (partial grill block on the extra vents on the bottom of the body kit)
• Full body pan.
• Sealed panel gaps (thinking of a way to do this without affecting the looks of the car). Weatherstripping didn't seem too tacky, but we'll see.
• Have no idea if fan is electric or mechanical, I'll have to look under the hood later today.
• Lighter weight wheels. More stylish, but aluminum alloy wheels that don't look like dinner plates. A sort of middle ground compromise :D
  
  Less idealistic mods, but still ideas:
• Economy camshaft swap (except for on a race track or in a Porsche/Mercedes, I've never driven really high above the speed limit. 3 over the 70 mph speed limit is max for me (8 warnings, 0 tickets). So as long as I can go 73 easily, maybe speed up to 80 for the random interstate in the middle of nowhere/passing people. I'd be cool with that. Jetta has a lot of zip, and the next mod would make up for the loss of pep:
• Second, bigger turbo = more compression.
• Manual or Automatic is under debate. Supposedly the DSG Automatic by VW is more efficient in it's shifting than a normal human being. So that's up for debate.
• Getting custom hood, roof and trunk lid made which are actually solar panels and look stock with a potential alternator delete (highly HIGHLY unlikely, but using my imagination).
  
  Not really mods, but style choices:
• Synthetic oil, was going to do it anyway
• B5 biodiesel (max recommended on a 2011 Jetta TDI). Whether bought at B5 or adding 2.5 L (aka .73 gallons) of B99/B100 diesel to get close to B5.
  
  Some of these are easy weekend changes such as the lowered suspension and the body pans. Body kit (if it's direct bolt on) also could all be done in a weekend and will hopefully have built in tire spats if the car isn't already super low, if it's super low, it's almost acting like an air dam. Obviously without the grill block though, that'll take some fabrication. Maybe some
  

Any help will really be appreciated.

If VW are selling their BlueMotion versions in TX, get one of those - they're optimized for fuel efficiency.
If they're not selling them, read up on what VW did, and apply it to your own car.
Lowering is part of the game - get it lowered from the factory if possible.

More efficient cam shafts ... what VW puts in is already rather efficient.

They come with synth oil over here.

The DSG is supposed to be less thirsty in official tests.
A friend of mine has an Audi A3 1.9 TDi with DSG, and while it's very decent when shifting, it's also using a lot of fuel.
Like 40% more than his earlier A3 (late 1990's) true manual with a 1.9 TDi.
Only 36-40 mpg US, while I drove his older A3 to over 50 mpg without even trying !

The current VW TDi's aren't as frugally efficient as the earlier ones.
And they are rather complex machines, with soot particulate filters and all that.


Tinkering with the complex engine and peripherals will require skills - and void the warranty ;)

+1 to everything that EM said + the fan is electric and not mechanical.

How about getting one of those bolt-on reverse beeper kits, the ones that come with 3-4 detectors you fit into holes in the rear bumper. Fit the detector to the sides instead of the rear and wire it so it activates with the indicators.

Indicate and something is there it beeps. If nothing then silence, or at least a calm beep so you know your flashers are going.

Disclaimer - I haven't tried this but the cheaper kits are low prices enough to risk it not working.

Too bad.

Have a look on the web to see what VW did themselves - there are Bluemotion Golfs, Passats, Polos (don't think you'll get that in the US, it's the size of a Golf II / III ) , ... .

Yes, it includes a grill block , the most common mod done here ;)


The bluemotion models are always manuals.
If you have a chance to get a manual, do so if you want the best fuel economy.
(The DSG also adds weight.)

The higher dynamic compression from a bigger turbo would be the result of stuffing more air in there. The physical compression stroke wouldn't change. Stuffing more air in means stuffing more fuel in to keep the ratio correct. More fuel and more air means more power, but you really don't need any more, as you have stated.

A bigger turbo also kicks in later, which move the spot of best efficiency around. You would have to look at where it ends up, and where the loads are that you drive at, to decide if it is a better choice. A smaller turbo might end up being better for fuel efficiency, who knows.

The standard turbo is the VNT type (or more modern version) which changes the windmill side of things to respond better depending on the exhaust pressure moving over it. The VNT parts can 'stick' with time and gunge but some additive and a quick 'blast' usually frees it. It also means that the turbo you have is probably best suited to the car already.

Unless you are after mega power then leave it. And if you are a remap will get you more for less money and fuss. Also check out the TDIClub forums - I have heard / read that the 2.0 is more of a "delicate flower" when it comes to power boosts than the older 1.9.

Its a damn efficient engine as it is. Although what EM says about it being more thirsty than the 1.9 is correct it responds superbly to ecodriving especially the manuals. I can get Mrs A's Octavia (think identical to Jetta Wagon but with different badge) TDI 140 to over 55 MPG imperial in just town driving. I haven't measured a tank of that as Mrs A only lets me drive it sparingly and she sees the go pedal more as a switch than a lever.

So, different take on this topic:

You have a 2011/2012 Stock Jetta TDI, what would you do without making it look fugly? Like putting pizza pans on the wheels is out of the question.

1 look at the different posts on increasing tire diameter slightly 3-5% if you do enough highway driving, this is a given.
2 increase the psi to 40+.
3 us nitrogen instead of air. I have the automatic air pressure system on the Q45, tells me the psi of each tire instantly. with the nitro it si always the same. not effected by heat.
makes the tires last longer and consistant psi gives consistanly better mpg.
4 Do a kit, don't lower the suspension. I don't care what anyone says, it will make the ride suck. And why compremiss a perfectly well balanced and tought uot suspension.
5 Instal a scangauge asap. It's like a video game. Mount it were 1. you can see it while driving....not down in the ashtray!!!! AND wher you can easily touch/reach the buttons.
I found that the more interactive I am with it the better my mpg
6 get those window visors- the 2 inch plastic wind things that allow you to lower the window 2 inches without really effecting drag.
7. If these are bought new, change the oil at 500 miles, then at 1200 miles, then at 2000, then at 5000. THen follow the recommended changes.
why you ask? Because mulitple test have shown that 70% of all engine wear takes place in the first 5000 miles. Replacing the oil repeatedly removes the wear particles that are creating the additional wear. I did this on my daughter's KIA 2006 sportage v6. The I had the oil tested by Blackstone at 10k. THey commented that this seemed to be a little better motor than most of the kias and that I was lucky. I called and told them what I had done. They said one of the guys in the lab had guessed that I had done mulitple changes to achieve such low wear.