Just started! '98 Jetta TDI

[D_Bat]

I'm new to the board. I am finally getting a little out of my speed craze. I used to drive a turbo'd VR6 Jetta that got nearly 12mpg daily and now that I drive 140 miles round trip three days a week that had to go.

I bought a Jetta TDI that is getting an even 45mpg every tank with no mods and I'm hoping to up that fairly soon. I've gone through about six tanks now and I want to hit at least 55mpg, more would just be icing on the cake.

I do a lot of car work. I turbo'd my other car, have replaced almost everything from valve springs to brakes, to bearings, to transmissions and clutches, and to gas tanks. I've also fabricated up brackets and boost piping with my welder.

[tasdrouille]

Hi and welcome to EM!

140 miles round trip, you'll want a taller 5th. You have a .681 and a .658 to choose from. Gear is $350 + install, but you can always sell your TDI stock 5th for at least $100 to gassers looking for longer, but not too long, legs.

[D_Bat]

Yeah. I've been eyeing those for a long time. A long time being just as soon as I got it but haven't had the cash up front for the longer 5th. Here in Florida especially since all the roads are flat and the highways are set to 70mph. I think it's a 600rpm drop from what it is now with the new 5th which would put me around 1900-2000rpm at 70 which is darn near perfect. What have you done to get 60mpg out of your tdi?

[trebuchet03]

Originally Posted by D_Bat

Yeah. I've been eyeing those for a long time. A long time being just as soon as I got it but haven't had the cash up front for the longer 5th.

100+ hypermiling / ecodriving tips to increase gas mileage - EcoModder.com

Cheapest thing to adjust is you

[tasdrouille]

Originally Posted by D_Bat

What have you done to get 60mpg out of your tdi?

I keep the revs low, which without a taller 5th means driving slower.

[D_Bat]

Yeah. Most of those driving tips I do when I drive. Sometimes I am in a hurry and feel rushed and don't apply the gas saving driving but I'm doing better here and there. Most of the time I shift at 2k rpm, barely put the foot on the gas pedal, and leave it in gear and downshift without hitting the gas to slow down and slow down way before the light/stop. Not a whole lot I can increase as far as driving habits until I get one of those Scan Guages. That will show my bad spots. For highway I have recently been following about 50-75 feet behind semi's to catch their wind breakage and draft them. Mythbusters did a test and 100 feet behind they still got a gain which I'm sure you guys have seen. The best I've gotten is 45.9mpg. I know I can hit 46-47 for a whole averaged tank but that'd be the highest for a completely stock TDI with 0 mods and a mix between city and highway driving. I guess the mileage is about 1/4 city and 3/4 highway.

[Red]

Welcome to EM

[Irukandji83]

In what little time I have been a diesel fan, I've learned of an interesting system that gives you better mpg as well as a little more power. It's called water/methanol injection and basically it increases combustion efficiency which equals more power and fuel economy. I think full kits cost around $600 and you can see a 20-30 hp boost along with a 4-6 mpg increase over your baseline. There's a trunk mounted tank you fill with the water/methanol mix and it's up to you when you want the system to be activated. I know it's a bit pricey, so i guess this is just something to keep in mind for later! Best of luck!