I've been searching this forum all day and can't find anything. I've heard that there's an ecu upgrade the will make the g35 engine run on less pistons in lower rpms and all pistons in high rpms.

is this true?

 

err... are you sure?

if it's a simple matter of programming, it'd be done by infiniti already to raise mileage figures.

 

the ecu update would decrease HP and Torque figures... not something infiniti would like to do...I don't mind if the gain in mpg is verified...

 

Not likely. If the vehicle wasn't designed to shut down cylinders, I don't think a reprogram would change this. There are many things that need to be altered to make this successful... shutting down injectors, proper balance of pistons and crank to offset working pistons, etc.

All companies that have motors that do this advertise it, I have never heard of Nissan/Infiniti offering this on any of their vehicles sold here, and have never heard of this on a "performance" vehicle (except, possibly, a Cadillac).

 

If your worried about MPG you should sell your car.

 

 

oh really helpfull... why do you guys bash anyone who tries to improve on a good thing? I love my G, and there's nothing else I don't like about it. not that its any of your concern, I get 16-17MPG on a regular basis where many are getting 19-20. I don't drive like crazy nor do I drive like a papi. so with soring gas prices that you might've didn't hear about, and a prospect of 6$ a gallon not that far fetched nowadays, it's always good to explore ones options.

 

I also have not heard of any device that will allow the type of operation you are describing. However, it may be possible using something like a UTEC to tune for mpg rather than performance... In fact with the multiple map option, it makes sense to have a "mpg conservation map", which you can switch out on the fly as desired.

 

<strike>do you know of a site that talks about this? sounds interesting.</strike>

I'll search this forum first.

any other ideas ppl?

 

I'd say, and not trying to be a smart ***, that if you are getting 16-17 MPG then you really need to get off the fun pedal or try to slow it down. I'm getting 22-25 MPG with a few mods even.

 

people get crappy mileage for like the first 10-15k miles...it gets better when the engine breaks in...if you want better mpg do a few things:

1. check your air pressure in your tires once a week
2. keep up with regular oil changes
3. change your air filter regularly or upgrade to a k&n filter panel
4. don't run the ac at full blast or the stereo all the time
5. get rid of extra unneeded weight (on you and the car)

 

Lots of information on the UTEC on this site and at my350z.com (I think UTEC is an acronym for user-tuneable engine control). It is considered one of the best engine management units around as it "talks" directly to the engine rather than just modifying the stock ECU communication. It is also expensive ~1000, but software is provided so if you know how to tune a VQ you can go at it. Although most use it for FI applications, some have reported getting good gains out of their NA mods using it.

 

It's hard to compare gas mileage with cars in different regions because of different gas formulations. The gas in California, for example, is formulated to burn so clean that we take a couple mpg hit. Mileage also varies between seasons. I have a 5AT coupe that I put 91 into and don't drive hard at all (it almost never gets above 3000 rpm). Even stock, I never got more than about 16.5 mpg.

 

I do the same and I get 26mpg consistently...

 

Displacement on Demand systems like the you're talking about is a very complicated system and it's not something that you can simply program in.

DOD systems are usually only employed on vehicles with larger V8s that can pull the car around on 4 large cylinders. Anyway, these DOD systems are a farce and really don't help much in terms of MPG. Also, they ONLY work in light load situations like cruising which is really pointless because this is where torquey V8s achieve excellent MPGs because they typically turn extremely low rpms in high gear. C5/C6 6MT Vettes consistently see 25-27mpg on the highway because they're rolling 1300rpms at 75mph and these cars don't have DOD.