advancing timing for more mileage?

[sc2dave]

Is it possible to gain mileage by advancing the distributor timing some? '95 le 4cyl.

[73sport]

Yes, but there are limits whereby it could hurt the bottom end by means of detonation under heavy load at takeoff for example.

If the ECU steps in, I could retard it, if it thinks its pinging. I don;t know bout the ecu on that ride.

The idea is this, the spark is there sooner and you get a longer burn time therefor a thorough burn of the fuel in the combustion chamber before the exhaust valve opens and dumps your precious 91octane fuel.

If you try it, just go a few degrees at a time and listen carefully to the engine for signs of pinging and detonation. Look at the plug before you test and during testing. If they get peppered with little balls, its too hot and you need to retard it.

[flyeri]

Any gains you get will minimal. The manufacturer sets the timing where they do for a reason. It is certainly not to give us a lower mpg. They are seeking a balance of timing advance that will optimize performance, mileage, and minimze the potential for damage to the engine. This setting has become so critical that the engines have knock sensors that retard the ignition timing when the knock is sensed to prevent damage. Someone had set my daughters timing too high and she would hear it knock. Immediately the sound would go away because the ecu retarded the timing. I set it back to the recommended setting and the knocking stopped. Her mileage stayed the same as before.

[carsrus]

Yeap only bulletproof way to save gas is to drive like a granny. Tuneup and tire pressure can also squeeze a mpg or 2.

[wuda pig]

For about 7 months, my camry was at 20 deg BTDC using 87 octane. I did not know my timing was advanced and i didnt notice any improvement in mileage. I would usually get 300 miles before fill up. Now that my BTDC is at 10, i get the same mpg.

[sc2dave]

does a 95 have a knock sensor?