Fuel Consumption went up after the header+tune?
 

Hi There,

I would like to know your experiences on fuel consumption after changing header and then get tuned.

My plan is to get the header (catless EL most likely) and tune (via OFT or Ecuflash, I haven't decided which way to go...)

I have read in here of a member using tunes from difference sources and get very far difference in fuel consumption. He mentioned that his car drank like a V8!!!

Your kind sharing of the your set-up, such as type and brand of the header and the tune you are/were using (like OFT or custom tune or other sources) will be highly appreciated.

Thank you in advance for your kind input.

Just going to say that fuel consumption is just as much how you drive as what you drive. A well-rounded tune should not affect your fuel consumption much, if you can adapt your driving style to the new mappings. Theoretically, a good header should increase efficiency.

I run a modified oft tune with stock header. Stock to OTS OFT did not affect fuel consumption on the highway, but "city" driving efficiency suffered a bit likely due to changing the throttle mapping and me not adjusting. Plus it was exciting and new, so I was more aggressive on the throttle for a bit lol.

After my modifications, fuel economy suffered a bit again, but that's one thing I'm not overly concerned about.

The stock tune actually runs fairly rich, so if you keep your driving habits identical, I'd expect to see better efficiency from a tuned car.

But, once you install a header, you will want to rev it out a little bit more between shifts, etc., and your mileage will suffer :D

Crap, so that's why mine went from 31 to 22mpg... I guess it makes sense now

MPG didn't change on me from all stock to a UEL header and modified OFT tune. 20 MPG is average now(18 mpg if I drive like a maniac) but that is all city and very short trips.
Taking it easy, I can squeeze out 25 MPG, again with all short city trips. 90% of the time, it's a 5 min. trip or less. On highway and driving normal, it gets back up into the low thirties.

Keep the closed loop fueling as lean as possible in the load rpm range where you do your city and highway Cruise.

Refer to the thread that have me worried...

http://www.ft86club.com/forums/showp...18&postcount=6

That seems very abnormal fuel usage. 1.6lr/km? 62.5lr per 100km? 3.76 mpg?
Certainly not normal for most twin setups, including aftermarket header & tune ones and/or forced induction ones. I rarely seen mpg number changes more then +/- 20% for same type of driving, which easily falls on how heavy foot on accelerator is.
And as people are posting, better tune/header can be even more efficient, running leaner/better optimized, so more then probably changes to worse may come from if header & tune were installed for performance reasons, then lead foot to get that performance/extra fun and thus hits to consumption is more probable :). Without trying to drive as similar as possible prior header+tune change and doing throttle logging pre-post upgrade to eliminate variables it's hard to claim for sure if and how and because of what fuel usage changed.

I was referring during spirited acceleration in low gears low speed, of course those are not average fuel consumptions
It is just that I appured that with wayne's cam timing i got more fuel consumptions in those particular cases but the car drives better and smoother so it is ok, cam intake advance is morr aggressive on wayne roms
I think also there is some strange valve overlap happening cause at low loads on overrun with very few throttle i get some very light exhaust pops so i guess there is some fuel being throwed out to the exhaust

I still get better mpg on cruise and higher loads driving

During "spirited driving" .. or even during worse then that, track driving, with mostly just accelerating and braking on track/redlining for most acceleration on stock NA worse i've managed is 30-35 lr per 100km on track. I doubt header & tune to make it that much worse as numbers cited in that post.

"Spirited driving" sits somewhere between track & normal daily driving & if anything, closer to later, as after all there are still legal speed limits, how much you can endanger yourself & others & how much risk to total car is acceptable within uncontrolled environment, which public roads are. A bit higher revs, a bit faster taken turns .. certainly not driving near very limits of car as on track, where you don't have to keep in mind opposite direction traffic, some pedestrians won't run on track, if slide off track then w/o breaking wheel/suspension against kerb, no cars merging from blind junctions, safety equipment mandatory, staff with flags regulating driving according what's happening on track, thus one can allow to push car depending on skills and car capabilities. Not so during "spirited driving"/"canyon runs".

I didn t cited redline or high rpm in that post, but i was referring on medium to hard trhrottle during low gears low speed like for example starting from stops or acceleration on 2nd gear on low speed. With wayne cam timing I see higher instant consumption that what I get with more "classic" cam intake advance
That s a fact on my car and i m not inventing things, anyway average consumption is not high
You can try wayne cam timings and see if you get the same thing as me

When watching the instant mileage I can get almost that bad when fully stock. I don't even know the point behind having an instant reading since it is meaningless.

it is almost meaningless but well, with those cam intake i reach lower instant mpg than with stock or ots v2 or v4 cams

The tune removes the torque dip which was intentionally done by the factory to optimize fuel economy. Well worth sacrificing .