advance my timing for mpg?

[rocketman]

Has anyone advanced their ignition timing to increase mpg? How much did you advance? Performance issues? Just thinking about it . . . my '89 regularly gets about 30, unless I put my foot into it, and I was wondering if anyone has played around with their ignition timing to increase mpg.

[88lxi-shortram]

30 sounds pretty good compared to what some of us are used to. trust me just enjoy the 30 MPG dude... some of us are getting as low as 16-18.

[limikjr]

Every 100 miles I put 6 gallons in to fill it back up. That's about 16 mpg...

[MessyHonda]

wow i miss the 30mpg days...i was down to 25mpg when i was super feather foot on it

[rocketman]

Wow! 16-18? I always get high 20s if not 30 mpg. I think I'll try to advance a degree or two, watch my shifting, see what happens. Right now I'm trying to see what I can get out of my '89 so far as mpg . . . recent tune (plugs, wires, rotor, cap), modified air cleaner with K & N, 2 pounds over tire pressure, front spoiler, synthetic oil, less restrictive exhaust, careful driving. I got 35 mpg with one tankful . . . 25% city and 75% highway. That's about my best mpg so far . . . and the '89 has 525,000 miles on it. Our '95 Civic gets 40 all the time, 45 on a trip. I'm going to incorporate the mods to it when I finish this "testing".

[Dr_Snooz]

I can get you 4 mpg if you go back to the stock air filter.

https://www.3geez.com/forum/showthread.php?t=63700

I'll get you a longer engine life too. Those K&Ns don't filter so good.

I know that every magazine article on improving your mileage says to do a bunch of performance mods, but my experience has been that performance mods always hurt mpg. Given that advancing timing is a performance mod, I would expect it to hurt your mileage. As a general rule, I'd say you'll have better luck doing the opposite of what the performance articles tell you. If they say open the exhaust, restrict it. If they say advance the timing, retard it.

If you're going to advance it, I recommend using the highest grade gas you can find. Higher octane resists pinging. Our engines have no knock control like newer cars. If they start pinging, they will keep pinging until they beat themselves to death. You don't want to save a few pennies on gas, only to spend a few thousand rebuilding the engine. I would tell you to listen for pinging, but my engine was pinging really good and I never heard it until I drove through a narrow tunnel. By that time, it had been pinging a long time.

There are a lot of ways to improve mileage:

1. Reduce weight - swap for lighter rims, get a motorcycle battery, throw out the back seats, swap body panels for carbon fiber equivalents, replace glass with Plexiglas
2. Practice hypermiling techniques - just don't get bludgeoned to death on the side of the road by an enraged fellow motorist who doesn't think that 55 mph at rush hour in the fast lane is an acceptable practice
3. Play with aerodynamics - your spoiler is a good start. Follow it up with side skirts, rear diffuser and lower the car.
4. Swap in a smaller engine - ha ha

Also, be careful using cruise control. If it's not working right, it can really hurt mileage.

Let us know what you learn.

[rocketman]

I'll give that a try . . . an original paper element filter is going on today. So far as the other ideas . . . I don't carry much in the trunk, just a tool kit, spare, jumper cables and a quart of oil. I always thought that advancing the timing was the way to go, but I don't know for certain. Rocketman

[gp02a0083]

with an engine with over 500k miles, im just impressed if it can hit 24-28 mpg. Considering the use it has, carbon buildup and all that other junk

[2oodoor]

VERY GOOD ADVICE DR SNOOZ, EXCELLANT
ESP THE WEIGHT LOSS, MOST OF US DONT REALIZE HOW MUCH CRAP IS IN THE TRUNK... LOL i RECENTLY STARTED BACK DRIVNG THE LX AND ENJOYING THE FRUITS OF MY LABOR.. THEN I REMEMBERED THERE WAS THE EXTRA TOOL BOX, A BOAT BATTERY, TWO SPARES, COUPLE OF PULL BARS AND CRAP LOAD OF 3GEEZ PARTS BACK THERE.
I PUT ALL THAT IN BACK OF THE HATCH FOR NOW AND WOW WHAT A DIFFERENCE THAT MADE. THIS CAR IS A BLAST TO DRIVE AND PICKED UP MPG AS WELL, NOT SURE HOW MUCH SINCE ITS A BLAST A BIT TOO MUCH SOMETIMES BUT HAVENT HAD TO GET GAS YET THIS WEEK, NOT EVEN CLOSE YET AND TOMMORROW IS THURSDAY.

[rocketman]

I picked up a new paper element air filter at Wal-Mart yesterday and will install it this afternoon . . . I also expect to advance the ignition timing 2 degrees. I will return it to specs if I hear even 1 ping or knock. I'll let you know about the mpg next weekend. Rocketman

[frantik]

3. Play with aerodynamics - your spoiler is a good start. Follow it up with side skirts, rear diffuser and lower the car.

i don't know about mpg but i noticed better handling and road grip after adding my lip and ducktail spoiler. i swear even adding the sunroof visor added some downforce

i have a CAI and a dc header and i dont keep track of mpg but it's around 30ish on the freeway and i'm a leadfoot

[MessyHonda]

just drove from LA just now and the best way to get good MPG is to follow the front car kinda close....i got 30.5mpg going 80mph

[AccordB20A]

i swear as the price of fuel goes up the quality of the fuel is going down. i get 9 (kilometers / liter) = 21.1693125 miles per gallon open road now. the same engine last year got me a 14km/liter flat over 600kms

[rocketman]

Well the timing advance and new air filter seems to have boosted the mpg . . . I think that I'm up to 32 but I only drove 650 miles in the last 3 weeks (used 20 gallons), but I went up a grade from 87 octane to 89, a dime more a gallon. No pinging at all, and I listened very closely. This weekend I'm going another 2 degrees. Rocketman

[YK86]

I'm curious but are you trying to raise mpg even if it means more $ at the pump? Raising the advance and using the right octane gas should net you a small performance gain but not sure about the mpg.....

If I recall, I think you need to go up in octane 1 grade for every 2degrees you advance. This was the rule of thumb for my 4.6L Mustang with a timing adjuster so the Accord might be a bit different. I ended up running stock settings because I had to get 93 octane to advance it 5degrees to get 5HP or something which wasn't a big increase for daily driving for that car.