mods and effect on mpg

1.9 TDI Awd

Veteran Member
Joined
Nov 20, 2010
Location
Marquette, Michigan
TDI
2000 TDI Golf 5spd
That's a no brainer. Slowing down 10 mph will make a significant impovement, more than anything else the OP's "mods". Aprox 5 mpg increase.
I would say of course it does, but im more curious in the amount it makes. i drive 7 hrs from my house to my parents house and if i drove a little slower im curious approx how much would be saved. but ill keep to my 10 over instead and let other people figure that out haha:D.
 

Mako

Veteran Member
Joined
Apr 4, 2011
Location
Cape Town
TDI
AMFPolo 1.4 TDI 100%Biodiesel, AHF Golf TDI 100% Biodiesel, AHF Golf TDI Wagon 100% Biodiesel, VW Syncro 3CT Kombi 100% Biodiesel, Corsa 1.7D 100% Biodiesel
Timing.........Euro maps seem to run a few more degrees advance than US versions. PD's can only change timing through software changes.
 

MikeMars

Veteran Member
Joined
Mar 6, 2008
Location
UK
TDI
Vento 1.9 TDi (retired), A4 1.9 TDi (rear end collision), VW Passat 1.9 TDi (retired), Audi A2 1.4 TDi
There are very few mods which are financially worthwhile from the MPG viewpoint given the cost of parts & labour. If you have to change something because it is worn out anyway, then it does make sense (for example, fitting LRR tyres once your existing ones have worn out).

Changing driving style / speed is the main way of improving MPG.
 

etag1949

Veteran Member
Joined
Aug 17, 2008
Location
Newtown CT
TDI
1997 Jetta,1998 Jetta(sold)
Got my '97 in early may from NickS (megaladon6) with 174k on the clock. Only performance mod is balanced pp520 nozzles and IQ adjustment when installed unless you count dropping the exhaust behind the mid-pipe. He said he was getting 43-45mpg (IIRC) mixed driving with syn-oil & power service every other tank. He got it at 105k and never cleaned the IM (I'm at 184k and haven't cleaned it either).
My daily round trip is 110 miles.
I use cruise whenever I can.
I don't use AC - windows cracked; vents open wide.
The belly pan is missing.
Early on I got 46-48mpg per tank (85-90% highway 65-78mph) mixed traffic (Newtown <--> Hartford) with or without PS on 215/40/17 tires.
Changes made (in sequence):
Add 4oz PS every fill - 48-49.5mpg
Stock steelies & POS snows 195/60/14 @40psi - no change
lower shift-point RPM (1.5kdown/2kup) & highway MPH by 5-12 (not above 68mph) - 53.4-53.8mph last 2 tanks & looking about the same on the 3rd.
Changes I'd like to make to improve further:
Kumho Ecsta LX Platinums (touch better than the Solus KR21 IMHO)
2.5" hi flow dp/cat/res/pipe exhaust
.681 5th (1st-2nd syncro grind + original clutch) when/if trans/clutch work needed.
bigger CAI (& possible IC/piping)
underbody flow improvement if I move the drivetrain out of this "road warrior" body (mk2 Jetta preferred)
I drove my stock '98 150k without cleaning the IM (it's ugly in there), adding PS with a 70m daily round trip and alternate weekend 450m jaunts to Cape Cod. Started at 48-50mpg and ended at 40-44mpg.
My uneducated experience tells me that nozzles & IQ adjustment picked up 2-4mpg, PS helps with the IM as well as picking up 2mpg and lowering speed & shift points can pick up 4-6mph.
 

Turbospool

Veteran Member
Joined
Sep 15, 2007
Location
Daleville Va
TDI
2001 White TDI Jetta, 280k, 2003 jetta 270k
While it is true that there are very few mod's that will pay you back in "Bucks" it certainly does improve drivability and actually does net better mpg. One does not need to split hairs to get which one acually did what. I will simply share what I experienced in a pkg of upgrades that netted me 10 mpg hands down. I also gained a terrific power upgrade that makes my car FUN to drive as a daily driver. Bash me if you will.... but here's what brought about my fun/mpg improvement.
1. scanguage II for right foot training.
2. Tires inflated to 2# below tire rated max
3. Open exhaust , 2 1/2 downpipe, 3" tail for better breathing (out that is);)
4. Sprint 520 nozzels calibrated by Drivebywire
5. Rocketchip stage #2
6. Advanced timing, and IQ adjustment
7. Thermostat replaced with 190 Auto zone replacement , now I see 195 temps instead of the 170 I was seeing before.
I keep my car in clean oil every 10-15 k and fuel filters, air filters maintained, keep her clean , and see back to back 60+ mpg all summer. I bomb around on occasion as well. It's just an experience , I know , some here will know better ..... but this works well for me. Some of the above mods cost money, some don't, pick and choose what you wish. I would'nt go back and leave any out . Happy TDI'ing :D
 
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