mdecsi

Changed the thermostat yesterday afternoon with a friend of mine. Because I don't have the necessary tools nor knowledge to set the timing, I did it without removing the timing belt. I hated it, and never want to do it again.

Engine temp is now very stable around 90C (~190F). The old T-stat looked a bit dirty, but it looks operational. But, it was a cooler one, 80C was stamped on it (176 F). I believe it was operational, but opened earlier then the official 88C thermostat. Maybe it was intended to be used in warmer climates.

Oh well, now there is nothing to do, but driving and calculating fuel consumption. A job I like to do.

I hope I will be able to save a bit, because gas price is on all time high here, 390 HUF/l, that is about $8.2/US gallon.

Thanks for the advice.

Loudgoldwing

Didn't even realize you could change the thermostat without pulling the timing belt.

190 degrees F is a MUCH better t-stat for these engines. My '98 also has an AFC 2.8 12V in it. My T-stat is a 192 degree F model. The car runs happiest at about 204. The cooling fans kick on at 210.

With a few mild mods (cat-back exhaust, injector nozzles and a soft-flash chip), I got almost 28 MPG on a recent road trip. But the big number is that I'm averaging about 25 MPG commuting +/- 15 miles each way to & from work. That trip ranges from 45 MPH down to 30 MPH, in a combination of suburban & city traffic.

mdecsi

It is possible, but you need 3 hands, a lot of patience and a first aid box to treat your wounds afterwards.

These are excellent numbers. Let me ask you about it:
- "cat-back exhaust": what kind of exhaust is this? is it a tuned pipe connecting the cat and the muffler? did you buy it or custom made it?
- "injector nozzles": have you changed the stock injectors? why and what kind of injectors have you?
- "soft-flash chip": i believe it works only on OBD-II cars, am I right? mine is OBD-I, one of the last AAH engines.

Lago Blue

I can't answer your questions for Loudgoldwing, but I should perhaps mention two additional points:

When I got 32 mpg I simply did it purposefully in conditions that I can easily replicate (steady 100kph high-way; long trip; done in both directions; careful consistent fill-up method; and Google maps) for comparison purposes with my past and future results.

Because of the apparently very limited ability of the O2 sensors to correct the air/fuel mixture, I think it is important to ensure you have delivered the best conditions possible upstream prior, to allow them (the O2's) the earliest opportunity to be given control and to fully function. The V-stack mod to fix it directly into the front of the MAF housing; and the large de-posted MAF mods certainly allow me to see healthy full-range voltage outputs from the MAF sensor betwenn closed and WOT, but for our purposes here I think the more important benefit is the early and good sensor output (digestable by the ECM) <i>at low throttle openings</i>.

https://www.audiworld.com/forums/sho...hlight=mileage

https://www.audiworld.com/forums/sho....php?t=2789759

https://www.audiworld.com/forums/sho...highlight=tour