What is the best mpg i can't expect from a 1997 jetta td AAZ - page 1 - IDI Engine - VWDiesel.net The IDI, TDI, and mTDI source.

• What is the best mpg i can't expect from a 1997 jetta td AAZ by honda_vtec2 on 26 Jul, 2008 23:50
• Hi everyone, what is the absolute best mileage i can expect from a 1997 1.9 TD AAZ?
  
  What are the best tweaks, mods to use to achieve the best power/mpg ratio while driving this car. I've read most of the posts on here and noticed that 1 individual is getting up to 1000km by placing a k24 turbo on the car instead of using a stock ko3.
  
  I'm just looking for the cheapest/easiest mods to obtain better mpg on this car.
  
  Thanks
• #1 by homerj1 on 27 Jul, 2008 04:48
• I'm driving a 94 & 95 Jetta both have aaz motors and are high mileage cars,  ( 453,000  & 335,000 kilometers) with no mods - except the 94 is missing its mufflers
  
  My in town fuel economy is about 37-39 mpg consistently.
  
  I hope helps?
• #2 by Infinitrium on 27 Jul, 2008 09:48
• I had a 93 Jetta with an AAZ and the CHD tranny. No matter how hard I drove it, my fuel mileage never went below 40 mpg.
• #3 by honda_vtec2 on 27 Jul, 2008 14:34
• This 97 Jetta has the AAZ engine and i believe the ATH tranny. I'd really like info on what the best mods are to improve the mpg to around 50 or more.
  
  Thanks
• #4 by James8485 on 27 Jul, 2008 15:17
• i know i had a K03 turbo on my rebuilt AAZ and i got around 750 per tank of highway 115 km/h around 2800-3000 RPM i did the pin from the 1.6TD and then i did the pump mod where you join the 2 wires together and removed the switch on top the IP....reached around 800 k's now my last mod was putting a K24 turbo on instead of the K03 and i reach 950-1000k's now of strickly highway driving doing no more than 2800 RPMs
  
  when driving with the K03 doing this my boost was 10 PSI
  when driving with the K24 my boost is 4-5 PSI so my pin isnt out as far pumping in the fuel is what i recken. but ya 750 ----> 1000 with the bigger turbo
  
  alittle more laggy but wow when it hits its like driving a new car!! more MPG and More POWER!!!! cant go wrong!
• #5 by Dirtrag2 on 27 Jul, 2008 18:38
• X2
  
  my '97 AAZ on fresh engine got 750 per 50 liters, now with a T3 and 1.6pin 800-900km on windy, up and down country roads.  about 41mpg US or 48 mgp imperial.
• #6 by stewardc on 28 Jul, 2008 04:19
• My AAZ has a Giles pump, T3 turbo with 2.5" downpipe and exhaust, ported head, etc, etc, etc. I regularly get 55 mpg (Canadian gallon). However, it is in an 800kg Rabbit pickup.
• #7 by slorimer on 28 Jul, 2008 07:30
• In my 94, I am regularly getting 900-950Km per 51-53L, which comes out around 49-51 Imp MPG.  The only thing I've done is pumped up the tires to over 40 PSI, and slowed cruising speed down to 110km/h.  I disabled the daytime running lights, but any improvement is in the noise cause I just found out my voltage regulator is gone.  Also my wastegate is stuck closed so I see 25 PSI with anything more than very slow acceleration.
  Anyone know where I can get a used alternator for the 94 1.9L for under $100?
• #8 by numbnuts on 28 Jul, 2008 13:25
• i have been driving my 96 golf aaz with k03 for the last 3 months mainly to get me to and from work. This consists of about 5 miles in the suburbs so not too busy and then a 10 mile blast down the motorway at about 80mph. I am running 1.1bar boost a rover fuel pin and also the fuel screw turned in a touch, it needs more to really get it going but i haven't plumbed in the egt yet :shock:
  Anyway i am getting an overall 41 mpg and i don't hang about in it taking it easy. I do think the cth? 5 speed is a little to under geared as its revving too high in the motorway. I also have a t3 to go on when i get the time to rebuild it. I do think that if u run a bigger laggyer turbo and are not on boost as much, you will not be using as much fuel as before. With the ko3 i mostly seem to be 0.8bar and over
• #9 by honda_vtec2 on 29 Jul, 2008 16:11
• The guys with the mods, is your car smoking at all or does it smell like diesel and stuff. Thanks
  
  50+MPG on the AAZ sounds fantastic! I hope i'll be able to hit that and more with an old engine...lol
• #10 by honda_vtec2 on 29 Jul, 2008 18:38
• Quote from: "James8485"

  i know i had a K03 turbo on my rebuilt AAZ and i got around 750 per tank of highway 115 km/h around 2800-3000 RPM i did the pin from the 1.6TD and then i did the pump mod where you join the 2 wires together and removed the switch on top the IP....reached around 800 k's now my last mod was putting a K24 turbo on instead of the K03 and i reach 950-1000k's now of strickly highway driving doing no more than 2800 RPMs
  
  when driving with the K03 doing this my boost was 10 PSI
  when driving with the K24 my boost is 4-5 PSI so my pin isnt out as far pumping in the fuel is what i recken. but ya 750 ----> 1000 with the bigger turbo
  
  alittle more laggy but wow when it hits its like driving a new car!! more MPG and More POWER!!!! cant go wrong!

  
  
  James, I live in the Toronto area. I'd like to run a setup like yours, where is the best place to get the parts that you are using?
• #11 by dieselweasel on 03 Aug, 2008 18:11
• These 1.9s tend to not be as good on fuel as the 1.6s are.  Perhaps its because the mk3 bodies are heavier than those of the mk1 and mk2s...not sure.  
  
  I've had two 1.9s...my first was '93 Golf which always averaged around 37 mpg US.  Could never get any better no matter what I did, although got about 45 mpg US on it ONCE, driving 50-70 km/h through New England.  My second and current car is a '94 Jetta, so far it consistently gets 42-44 mpg US (50-52 mpg imperial).  
  
  On both cars I did the following mods and the fuel mileage definitely got better:
  
  -advanced inj pump timing to .039" ( most guys do this to their VW IDIs...I believe the stock setting of ~.033" was to meet emissions...more NOx produced as inj timing advances, but better power and fuel economy)
  
  -there is a valve with a solenoid on it right on the front bottom of the pump...it effectively prevents the dynamic timing advance in the pump from working below 3000 RPMs which is no good, so run a wire to it from the fuel shutoff solenoid which will keep fuel flowing to the advance mechanism all the time
  
  -keep tires inflated on the high side
  -rarely use A/C
  -rarely go over 100 kmh
• #12 by mattbondy on 03 Aug, 2008 19:24
• I would suggest checking out the www.vwdieselparts.com/forum general diesel forum. There is a sticky post regarding internal pump pressure. Most users on this forum are running vehicles with the 1.6 or 1.5 so Im not sure if their is any difference in the pump on the 1.9. (Someone above mentioned something about a solenoid controlling timing advance?)
  I think this is basically what Giles must do (adjust the timing advance mechanism) among other things. There is a systematic method of going about this in this post:
  http://www.vwdieselparts.com/forum/viewtopic.php?t=5936&sid=b42978438754b51e5cbb58d4ba6d78cf
  I just adjusted the timing advance piston and have been playing it by ear/ odometer but that is probably not the best way of going about this. There are holes that you want to avoid obstructing completely at the very least.
• #13 by honda_vtec2 on 03 Aug, 2008 21:24
• Thanks so far for the info and tips guys, please keep em coming.
• #14 by jtanguay on 03 Aug, 2008 21:37
• Quote from: "slorimer"

  In my 94, I am regularly getting 900-950Km per 51-53L, which comes out around 49-51 Imp MPG.  The only thing I've done is pumped up the tires to over 40 PSI, and slowed cruising speed down to 110km/h.  I disabled the daytime running lights, but any improvement is in the noise cause I just found out my voltage regulator is gone.  Also my wastegate is stuck closed so I see 25 PSI with anything more than very slow acceleration.
  Anyone know where I can get a used alternator for the 94 1.9L for under $100?

  
  
  25 psi? stock turbo??!!!! unless that is a K24 or T3 that is wayyy past the efficiency range  :lol: better get an egt gauge