Months ago I read about someone who had one of their maps be some sort of eco tune. Now that I drive further in order to get to work I started thinking this type of tune could be beneficial and eventually pay itself off if it works.

I did search but did not find anything. I hesitated before posting but I am really interested in a tune like this. I'm assuming a tune of this sort would be one of a few maps that would have to be tuned locally but I'm not sure.

Is a tune like this possible or not? and what approximate gains could be expected from a vq35de?

 

if you have a FI system and upgraded fuel system , it will kill your gas if you put your foot in it. The sure, you can turn down the boost and fuel and timing for a dinker map.

But if you have an NA car w some minor bolt ons etc.. theres no MPG improvement that you can tune in that will match the gains seen with driver input improvement.
You have a certain amount of air comming in period due to the mechanics of the car. Whereas I could turn down the boost thats forcing a change in the air comming in, NA cars cant.
You require a certain air fuel ratio for that.
you require specific timing to maintain driveability.
Aside from minor tweaks to these numbers, dont expect to see much gain at all. MAYBE 1 mpg.

Cruise control w a manual trans is the #1 way to get fuel effeciency.

go the speed limit and get there reasonably slow and you will see gains. Do not sue the gauge in the car to measure this btw.

Unless you drive at off hours.. you aint getting down the 101 at anything more than 85 or less than 70 during rush hour, and you WILL have to brake in between. It just is what it is man.

again, if you have FI, its a diff story.

 

Reducing timing, reducing fuel input (perhaps through a piggyback system) and couple it with conservative driving and fuel saving tires perhaps?

 

By default the ECU targets 14.7 AFR in low to mid-loads and anything leaner will cause destruction with time...pulling fuel without limiting throttle is recipe for disaster. In fact, it is impossible to set the target AFR greater than 14.7, the ECU simply won't comply.

The real way to do it is limit throttle to say 1/2 or 1/3, which is technically possible but I don't know anyone who has mastered the throttle tables yet (even uprev themselves) to accomplish that.

 

thank you guys for the quick response. Guess my thought is not possible. I swear i saw a picture posted with someone that had some crazy mpg on the display after a tune but I cant find the post anymore so im SOL for providing a reference.

 

Anyone with a modified fuel system will show higher MPG than normal in the on-board computer, since the computer is permanently calibrated to the stock system.

 

actually i'm going to disagree with this. Although cruise is way better for people that can't properly control their right foot due to lack of intelligence, cruise control isn't that great.

Cruise is based on speed which means when you get to an incline the gas pedal gets shoved down in order to maintain speed. The proper way to get high mileage (hypermiling) is to maintain a constant TPS (pedal) input. So during hills you will lose speed because the pedal will be held constant which improves mileage greatly.

With cruise my 4.3L v6 s10 gets MAYBE 20mpg on my trip home to indiana. With me driving and not smashing the gas down on every hill here in missouri (like the cruise does) i get between 27-30mpg in that same truck over an entire tank of gas.

so, maintain an constant gas pedal. increasing speed or even maintaining speed up a hill will cause the load to increase, injectors to open, and fuel to disappear. It sucks to lose speed going up a hill but personally, that 5-10mph i lose on those hills is worth the 7mpg increase i get over an entire tank of fuel.

 

wooden block under the pedal would certainly help too

 

Cobb ap actually allowed you to adjust the throttle very easily and 2 years ago. I been hoping for a while that uprev would have a similair feature.

 

Setting AFR target to ~15.5 and optimize timing to maximize vacuum will yield the best fuel economy. Also need to make sure injectors turn off under heavy vacuum/decel (like when coasting down a hill).

 

Lots of good stuff, but this guy is local to me. The issue for us is constant stop and go driving even on the fwys. Its AZ.. and it be QUITE flat.


IF you can keep it at 81 on the way to California from here, you can usually get by w out having to slow down or pass well .. and it stacks the distance per tank way up as comapred to not using the cruise.


The theory behind how the engine works is great n all, but the human input is the deciding factor in it all. And thats gets mostly eliminated using cruise.

 

 

ya, for stop and go here in stl i tend to drive slower and coast so i don't ever make a full stop. that's about the only thing that can help in those situations.

driving 81mph kills mileage too. most engines are designed for maximum fuel economy at 55mph. I noticed my truck dropping off huge on mpg after 65mph so i usually roll about 60mph on the interstate.

 

Uprev/osiris won't target higher than 14.7. The values go in, but it still targets 14.7. Quality tuning + throttle table limits are the best bet for getting better economy.

 

You can adjust it quite easily in Uprev too... such as allowing full open throttle. They don't include a 'slow/limited' throttle map built in (currently it's either stock, uprev tuned, or custom) but one could make their own with enough time and patience.

 

Aerodynamics play a huge role:





In all seriousness... Be careful about leaning your AFRs here in AZ. Our hot summers are less forgiving of a lean AFR than somewhere that's not so hot.

 

sub

 

just leaning your AFR doesnt usually make that much difference. You ign timing, injector firing angle. and cam angles also play a big role and all need to be optimized.

 

yes

 

Have you looked into different gearing options? Are you a/t, 6m/t? Swapping in an auto 3.353 into a 6m/t will bring down your cruising rpm and improve gas mileage, but you'll lose cruise in 6th gear. The lower your cruising rpm the better mpg you will get