Upgrade Nozzles: 520 DLCs

Advance timing to about 2' BTDC at warm idle for a little more power, adjust IQ to gray haze at WOT on take off should be around 2-3 on VCDS.

get a 195'f superstant thermostat

Block the upper grill (dont block the air intake part)

Change the timing belt and metal impeller water pump. (due at 100k)

Standard maintenance, change ALL the filters make sure all wheels are aligned and spin freely...u'd be amazed at how common dragging brakes rob Power / FE on the mk4's (dry lube brake rails..seriously)

2400ohm resister on fuel temp sender, (fools CPU to keep injection timing closer to optimum).... please note these timing numbers are for most american lower cetane fuels (texas, cali, and EU fuels + biodiesels have higher numbers...you've been warned)

2-5% bio-diesel blend for lubricity / injection quality purposes. can home mix or pump.

If you have a manual, changing the 5th gear is so satisfying...i chose 658 ... and im glad i didnt go higher or lower for my style driving / car.

DRL delete: On my car standard Lights on costs 4% engine load. I'm installing HIDs this spring.

Delete roof rack if you have it... seriously 4+mpg loss

clean all the carbon out of everything, yours probably has some

add a 750-1000 water block heater, and a 200+ watt oil pan heater... a warm diesel on startup is a happy diesel.

There are many other things you could do to get more power, but it starts getting weird... just as my Project DerpSpeed is getting weird on the other side of the coin... but Im happy i'm in the 70 mpg realm (70's mpg @ 60mph) and heading into the 80s with a few other major mods that are left this spring. (don't blow up on me, this is a 4 year ongoing project and things are getting weird like no cabin heat for 30 miles due to lean running)