I know this is kinda a strange question to be asking, considering this is an FD and we don't get gas mileage from the beginning... Alright, I know as soon as you hit boost your gas mileage decreases... however is this due to being high in the RPMs or because the turbo is running. If so, wouldn't N/S make it so the turbos engage at a higher RPM making you stay away from the turbos meaning better g/m... do you know what i mean?

 

It would only increase gas mileage if you had a stand-alone ecu and tuned it for less fuel in the lower rpm ranges.

No offense, but going non-sequential to increase your mpg 5% is pretty silly...

 

I agree -- no one really buys a FD for fuel efficiency.

 

IMO, it could work, at least a little bit and as long as you kept your foot out of it...but what fun is that? Who knows if there is a measurable/noticable improvement however.

But for the most part, I hate NS so you won't see me increasing my mileage anytime soon.

 

I'm thinking theoretically it would work, but...
Also, what causes the engine to burn fuel faster? The turbo, or just being in the high RPMS...

 

For the most part*, anytime that your injector duty increases, you are dumping more fuel into the engine. Boost or higher rpm will cause injector duty to increase. Temperature also will slightly effect injector duty, cooler = higher duty, warmer = lower duty (has to do with the density of air at various temperatures). But there's not really much you can or want to do about that.

Just in case you are new to injector duty;
40% inj duty means that for any given second, 4/10 of that second the injector is open, spitting fuel into the engine and the other 6/10 of the second it is closed. Now obviously, the injector will operate on a much smaller time scale as to give a basically constant flow of fuel. (it opens and closes rather fast, but i am not sure of the resolution)






*I say for the most part, because after watching my injector duty graph on my AVC-R, initially injector duty jumps up, then once boost builds past a few pounds, it abruptly goes back down (like 1/2). I am assuming that this is the secondary injectors coming on, which means that I am using more fuel from a smaller injector duty.

 

Gasoline engines generally become less efficient when they're running boost (extra fuel is dumped in and spark is retarded to control knock). High speeds will cause increased friction. High speed and boost really sucks fuel since you're dumping in even more fuel to keep exhaust temperatures down--to keep from melting the turbo (and exhaust valves if you happen to find yourself driving a piston engine).

So if you want to save fuel in daily driving (for the occasional backroad blast, of course), keep rpms low and avoid boost.

 

The greater your engine speeds/boost, the more air passing through, hence more fuel has to burn.

Is the logic behind your idea suggesting that more lag would make it easier to stay off boost, thus saying that N/S would help conserve fuel?

 

Well, here's my .02 cents...

It doesn't matter whether you are off boost or not, you are going to burn up gas. This is the wrong car to be concerned about gas mileage with... The only thing that is REALLY going to help gas mileage it more highway driving and less stop and go driving.

I've owned my FD for 7 years or so and have basically got the same gas mileage whether lead footing it or not. The difference is basically un-noticeable.

If you want gas mileage, get a beater Civic.

 

Staying away from the debate of milage and trying to increase it, the answer is yes, but obviously only in the lower RPM range. Less boost=less air=less fuel. Simple as that. Granted, it's not going to be much, but it will. It shouldn't be theoretical. Say, you're at 5psi now at 3500 instead of 10, or whatever. That in itself should give you your answer.

 

I'm not worried, its just that I'm wondering...

 

I must love arguing with you

Have you ever had a rebuild and been off boost for entire tanks of gas at a time? I got awesome gas mileage during my extensive 1000 mile no boost break in period. I was taking the car for many highway drives to rack up the mileage faster, but I was getting gas mileage in the 20 mpg range or so, whereas if I'm driving sometimes on boost, sometimes off, I see 15-17 mpg.

My 2 cents, not, it wouldn't increase gas mileage. Staying off boost and in lower rpm ranges will.

 

Did you read my entire message (let me answer for you, nope. ) ? I said the best way to improve gas mileage is to do more highway driving than stop and go, which is what you just confirmed.

Sure, if you do a lot of highway driving, your gas mileage is going to be high. However, around the city, it really doesn't make a difference. And yes, I had a break in period with my current engine. Didn't really make that much of a difference. The only thing that changes my gas mileage is the amount of highway driving that is added into the mix.

 

This very tough to do... I had to set my PFC rev limiter to 4150 rpms to keep me from getting on the gas...

Screw gas mileage! You have to PAY to PLAY !!!

 

Yeah, staying off the boost can be really difficult -- 450 miles left for a "complete" breakin.

 

For daily driving the answer is YES, you will see much better MPG averages.
Non Seq. I hit full boost at 4k rpms.
So daily driving Im shifting under 3500rpms.
Not being in boost and dumping fuel into the engine has shown a definite improvement in daily driving.
Now, as for WOT around town. as the others say.. you pay to play. and gas consumption is the same as in Seq.