Advanced timing = better fuel economy?

[Baltothewolf]

So as some of you know, I have been getting really bad mpg in my Mustang. Normal cruising speed at 55mph was about 21-23mpg. I went to test drive my friends supercharged Mustang he just got, and timing came up in conversation. He asked if I had ever messed with it, and I said no. He grabbed his timing light, and we learned my stang was at 8°, stock is 10°. He turned it up to 14°, and now my cruising mpg at 55 is up to 26? I drive the same route to my BF's house a lot, so I know about where my mpg normally reads.

Also, MORE POWER! It made a noticeable difference in my 1st and 2nd gear pulls :0.

TL: DR. Turned timing from 8° (was retarded 2°) to 14° (advanced 4° over stock) and gained 4mpg. Normal?

[GreenHornet]

Yes people have been tweaking timing for years to achieve optimal fuel economy and performance. Just don't go to overboard as your engine will start to knock. You can also add meth water injection to help suppress engine knock and add a little more gusto to your ride.

[Joris]

Advanced timing is better for fuel economy, up to a point ofcourse. The combustion of the fuel and air mix happens at the best moment possible, instead of a little late or to early. This way you get the most energy out of every bang. With todays fuels you can easily advance your timing a bit on older cars.

Advancing your cam timing also helps, because that shifts the powerband lower on the rev range. Combine that with a little loose valve adjustment for some shorter duration and lower opening and it should be noticable.

[jedi_sol]

also be careful with advanced timing, it will affect your smog emissions.

Back when i had my del sol, i swapped out the engine for a japanese engine. I failed smog inspection because my timing was advanced.

When i adjusted the timing back down to USDM spec, i passed smog, but now my mpg's noticeably dropped as well.

[Baltothewolf]

The timing takes about 5 minutes to adjust on the car so, it's not a big deal for me. When I need to smog it I can just revert it back to 10° and take it down.

Thanks for the information guys, I really appreciate it. I think I'm gonna advance my timing on my insight 2° to see what happens. As for knock, my body who advanced it found that 14° is safe for all stock 5.0's. Him and his brother have always run 14° with 87 octane with no ill effects. I just can't believe how much better the car runs now. It feels like am entirely different car.

[2000mc]

Originally Posted by Baltothewolf

I think I'm gonna advance my timing on my insight 2° to see what happens.

Insights had distributors?

[Baltothewolf]

Originally Posted by 2000mc

Insights had distributors?

No but I think you can still change the timing.

[redpoint5]

What elevation are you at? I know Apple Valley is the high desert, so I imagine you can get away with more timing tweaks than those at sea-level.

My Acura runs 40 degrees advanced on the freeway, and retards as needed when heavier loads are applied.

Try a little more advance?

[Baltothewolf]

Originally Posted by redpoint5

What elevation are you at? I know Apple Valley is the high desert, so I imagine you can get away with more timing tweaks than those at sea-level.

My Acura runs 40 degrees advanced on the freeway, and retards as needed when heavier loads are applied.

Try a little more advance?

I'm going to be driving the car down to long Beach a lot once it's dialed in properly, so yea.

[Miller88]

Originally Posted by Baltothewolf

No but I think you can still change the timing.

If it's on an engine that was originally made for a distributor, then it can be changed easily. You pull out the sensor that replaces the distributor and drives the electronic ignition, reindex it to be a bit advanced and it is set!