Injection timing vs. fuel economy

Does anyone know just how much of an effect retarded engine timing vs. slightly advanced timing has on fuel economy?

For example, I've suspected that my Passat's mileage has been poor lately, and I just measured the timing as 38/110. How much of a mpg difference can I expect to see by adjusting the timing to more like 60/130?

I'm sure you will see some improvement. How much I can't say but my mileage slipped to the low 40's when my injection timing somehow got retarded.

When corrected it bounced back up to upper 40's.

It's worth taking care of, especially this time of the year because it makes the car much easier to start as well.

Sorry I don't know the TDI chart well enough to quote numbers, but when my car was about 1/2way between "the line" and the bottom, I got around 37 MPG post-chip(42-43 prechip). Fixed the timing (up to about 1/2way between the line and the top of the chart) and my MPG is now back up around 42-43.

GotDiesel, LOVE the signature line!!

gotdiesel, only computer people like me and others would get the binary thing, it is funny!!

What's so hard about 0 & 1? /images/graemlins/rolleyes.gif It's too simple. /images/graemlins/shocked.gif

I'm pleased to report that we have 2 PC's and 2 laptops's in the house. Wife says I should get a 42" plasma screen TV instead of new car. /images/graemlins/crazy.gif Some thing's about the TV, it would be used by me more, it's cheaper and more fuel efficient, no license fee's or expensive insurance. /images/graemlins/cool.gif

Forgot to add I run about 2.5* advanced timing instead of the 0* that's normal setting. The came from the factory with it set at 2*, I bumped it to 3.5*, then put it back to 2.5* and last tank was 39.3 MPG with 3/4's of it in town driving. /images/graemlins/cool.gif

’02 Jetta GLS, Silver Arrow Metallic, Automatic, Cold Weather Package, TDIHeater, Tinted Windows, Turbo Diesel Badges, Audi TT Lift Pads, E-code Headlights, Euro Switch, Euro 5 Brake Light Mod, XM Radio, OEM Steel Skid Plate, OEM Fuel Line Shield, Modified Screenectomy, Ventectomy, CCV Filter, CAT 2 Micron Fuel Filter, EGR Adapted, Mobil Delvac 1.

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Old Navy said: (snip) Forgot to add I run about 2.5* advanced timing instead of the 0* that's normal setting. The came from the factory with it set at 2*, I bumped it to 3.5*, then put it back to 2.5* and last tank was 39.3 MPG with 3/4's of it in town driving. /images/graemlins/cool.gif

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__. On VAG-Com, there are two windows that read out the timing. (Did a little timing adjustment today) and one read 2.9 BTDC (this is the one on the left side) and the other would jump around if the accelerator pedal was pushed. It appears that this 2.9 BTDC is idle timing - is this OK? Thanks, MrG

Okay, I have a 96 Passat with the BK ECU, and was unhappy to learn that I can't change the injection timing on this one. What would it take, a new ECU? Would a chip change the timing, or allow me to change it? I wish the original owner had the TSB ECU changeout done.

Jerry