550km on 60 litres was what i was always getting with 440cc injectors, recently i changed to 750cc and retuned to suit and i got 400km and still had almost 1/3 of a tank left so id say it would do be getting the same 550 again.

 

these are completely rough mpg's for me the vary alot with how fast I feel like accelerating when you are cruising and staying out of boost you can be 20+. city driving is more like 14ish for me with stop and go traffic. If you go into boost often/alot more like 10mpg or possibly even worse.

If you stay out of boost its similar to what the car was stock maybe a few mpg's worse (kinda like a v8 sc400) unless you are on a long cruise then staying in vacuum the turbo actually helps some with the efficiency, but the first time you boost you basically loose all of that benefit. its an average unfortunately.

 

Are there any tricks to getting around let's say 22-25? This is about as much as I get on my dd. Id settled for that if its possible to get on an na-t

 

Or even slightly less than that and id be happy

 

I just did the conversion to your crazy imperial system and 21.5 mpg is what is equates to

 

I have averaged about 17 city and hwy combined thus far.

 

and what's your setup?

 

If you want 22-25 then you should keep the daily. the extra gas is just the cost of driving an na-t around and its not that bad unless you compare it to an econo car and even in stock form the 2jzge is not a gas sipper at all.

 

It might be because im really tired, but this was a lil hard to understand. My hope was that if my na-t build could make atleast 18 mpg, id sell the daily and just drive that. If i lose like 4-5 mpg I don't really care, It'd be easier to just maintain one car. plus that car would be a lot more entertaining to drive than my Subaru. So If I'm reading all of these replies correctly, 18-23 is about right? and achievable on the build im doing?

 

I've gotten over 30 mpg highway only. It was on a 500+ whp na-t mkiv on aem. 15.8 -16.0 cruise afr with around 40 degrees of timing.

 

Damn...how many pounds were you pushing? and on what size injectors?

 

880cc injectors, running with 18 psi. That was all highway cruise. That was the absolute best on a fill up on the way to tx2k13 with the cruise set on 80. I was running an r154 and an ls400 diff

 

keeping rpm low and staying out of boost is key to decent mpg, along with tuning of course.

http://my.is/forums/f114/taller-5th-gear-r154-users-505746/

 

wow did you acctually do that swap? ive got a 4.1 rear and at 100kph its slightly too low for my liking at 2650rpm although its pretty damn good on fuel. ps my fuel usage was 90% highway but boosted to 17psi and redlined first and second everytime i had to slow down and speed up after a town so no fuel econ run but my cruise was pretty lean at around 15.5-1. i do know of a guy who had his tuned by a master with the emanage and was getting 9l per 100km afterwards. really tuning the specific cells for cruise is pretty easy tho.

 

Im wondering if you guys can lean out your idle and cruise depending on tuning software. I know you can with standalone systems. We did this on a dsm and were running 16.0- to 17.0 on the highway with our one friends car. I dont have any fuel mileage numbers I know 3 of us drove to the same destination and 2 of us were at around 1/8th of a tank of gas from a full fill up. Our friend that leaned his car out on the highway (logging knock counts) used a 1/4 tank total. The rest of us just stared at each other. I know you can use an AEM wide band and just do a lean burn if you have the ability to mess with fuel tables.

 

you can but it doesn't do that much, I used to set my cruise lean in the 16-17 with the aem and I never had my gas mileage double. sure it was slightly better but not enough to warrant the increased cylinder temps from such a lean burn. give the car a chance to cool down after a long pull is what I prefer, not making it work extra hard to become an economy car when its about the furthest thing from one.

 

I always lean mine out in the 55 mph to 75 mph cruise area around 16.0. That with high timing numbers has netted me excellent fuel mileage without excessive egts

 

Exactly the same ^

Tuned to 16:1 at all cruise areas of the map, and I get better economy now that Im na-t, than I ever got with the NA engine.

It all comes down to driving style and knowing where to pick up the throttle and ease out of it, to maximise use of your cars momentum

I have had over 750km from a tank, trying hard to stay in vacuum.