Author Topic: Upgrades to improve MPG's (Read 5687 times)

superman293 · « **on:** May 23, 2006, 07:32:08 pm »

Hey there i was wondering if there was any modification i can do to my 2000 TDI to improve gas mileage and possibly power, would a downpipe, cutting off the cats or putting a high flow intake help with MPG's? or could it have the oposite effect and make the car consume more?
thanks

malone · « **Reply #1 on:** May 23, 2006, 08:38:18 pm »

Reduce weight - strip off unneeded stuff from your car. This may include carpets, rear seats, headliner, any plastic trim in your interior that serves no functional purpose. Get a lighter spare tire.

Avoid air-conditioning unless you're in a really hot climate and you need it. Take it out if you have it anyway.. the a/c belt causes drag on the engine.

Run 20% biodiesel (B20). Not only it costs less than regular diesel, it is quieter, smoother, better smelling, and a tiny bit more powerful or better in fuel economy.

Is your intake manifold clean? If unsure, check it. It's not uncommon for a TDI like yours to have soot clogging in the intake, which reduces airflow and hurts power/fuel economy. Make sure your TDI engine and rolling parts (no brake dragging, etc.) are in top shape mechanically.

If you have a snow screen in your intake, pull it out, it's junk.

Upgraded wheels can hurt mpg quite a lot.. stick with stock wheels (e.g. 15") and stock sized-tires. Avoid wide tires and larger or heavier wheels. Make sure the tire air pressure is up to spec.. throw in a couple more PSI per tire.

Every little bit counts.

I don't think modifying the MK4 TDI exhaust will make a noticable difference.

greggearhead · « **Reply #2 on:** May 24, 2006, 08:20:38 am »

I haven't had the pleasure of messing with TDis for economy, but on the old IDIs, lighter alloy wheels (not larger diameter and not wider) with skinny tires pumped up severla psi, like Malone suggests, made a noticeable difference. On a low hp car, it helped with accel, too.

I would think a free-er flowing intake and exhaust could only help - I don't know the programmers and chips well enough to suggest one or another or any that might help mpg over power.

Not to plug product, but on our water-methanol injection kits on 3/4 and 1T trucks, it usually increases mileage 1-2mpg (not towing, the towing value is about 1/2-1mpg improvement). I don't have anyone running one on a TDi that has reported back on mileage, but I don't see why it wouldn't help mileage on a 4 cyl vs. a big straight 6 or V8. It also helps to decarbon the combustion chamber and clean the intake, FYI.

Lowering the car a bit and possibly running a deeper front spoiler might help aerodynamics, but on a modern, more slippery car, it probably wouldn't help as much as on the old A1 & A2 VWs. Synthetic oil in the engine and transmission, and good wheel bearings with synth grease packed in the rears, and lubed brake pad sliders, etc. can only help as well.

macsdub · « **Reply #3 on:** May 25, 2006, 09:33:28 am »

opening up the exhaust and intake(airbox) will help efficency ,and the above posted mods will help too :wink:

superman293 · « **Reply #4 on:** May 25, 2006, 06:44:44 pm »

Now when you say open up the exhaust and intake you mean? downpipe and take off the cat, and a high flow intake?
thanks

macsdub · « **Reply #5 on:** May 27, 2006, 05:50:01 am »

um,yea,basically....
but guys/gals,doesnt removing the cat sometimes cause codes to be thrown???im not sure about that part
i usually fab up my own downpipes and intakes myself,ive yet to try this on an electronic engine,but im sure its possible with a little more engineering.