Improve MPG and power!?

[Niklas]

Good day all,

I've had my IQ for roughly one year and been a bit dissapointed with the power and mpg so I have fiddled around to try to improve it. It's a 2009 1.0L with roughly 100 000km on it.
A few weeks back tho I found something that did work quite well, a full power down of the ECU. The sequence I did was:
1. Disconnect positive Battery lead.
2. Try to start the car (obviously nothing will happen but engaging the contactors to the start engine will drain residual charge in any capacitors).
3. Wait 30min
4. redo step 2
5. reconnect everything again 
(before doing this I have done the usual and made sure that filters,oil,plugs etc are in good order)

When restarting my car again it had an unusuall high idle and I notice right away that there was more torque. Starting from a standstill and also keeping up speed in hills on the motorway is slightly improved. Took the car for a long drive last weekend, 600km, and it consumed 3,8l/100km (74mpgUK) for that trip which is 10% better than before(and it wasen't all high way). Note that I have been ecodriving for 10+ years and drive extremely consistent. Next week it's going in for the EGR warranty fix, I still have the old type.

So, this worked for my car, would be nice to hear if some one else wants to give it a try and report with results. It still have the uneven acceleration with what feels like missfires, I hope the EGR fix will sort that out.

[Anthony Poli]

Hi Niklas,

Sadly all you are achieving, is to put the ECU back into calibration mode for the first 800Km or so. Once the ECU has finished this calibration, it settles back to normal again. It does give the car more responsive feel, the fuel economy is usually worse.

Hope you have more luck with the other options.

 

[Niklas]

Hi Anthony,

I hardly doubt the system will calibrate for 800km and then dissregard the new calibration and run with old values? So far my car runs better and it's about 900km since I did the reset.

That was what I was trying to achive by cutting the power to the ECU, resetting it to start from a clean slate. This is usually the best way to make a control system adapt to new conditions(EGR pipe clogged up and what else) rather than letting it just integrate slowly over time. It can be a fluke that it worked on my car, maybe not. If someone is having the same problem (which I guess there is) they could try the same thing.

 

[Anthony Poli]

Hi Anthony,

I hardly doubt the system will calibrate for 800km and then dissregard the new calibration and run with old values? So far my car runs better and it's about 900km since I did the reset.

That was what I was trying to achive by cutting the power to the ECU, resetting it to start from a clean slate. This is usually the best way to make a control system adapt to new conditions(EGR pipe clogged up and what else) rather than letting it just integrate slowly over time. It can be a fluke that it worked on my car, maybe not. If someone is having the same problem (which I guess there is) they could try the same thing.

 

I was trying to say to, was the more sporty response would return back to normal.

It can't do any harm resetting the ecu, I was just commenting on my personal experience. Where the mpg was lower until the ecu had finished its initialisation.

The distance was a figure that someone else had quoted.

A obdii cable and a phone or laptop, might be an option if you have an intermittent problem.

Sent from my iPhone using Tapatalk

[mickburkesnr]

I reset the ECU on my Corolla, and the car has felt more responsive.

However, Anthony is right. The ECU only saves it's values to memory reliant on a constant feed of power. So when you disconnect the Battery it removes these settings. The power is then applied, and it's like a brand new ECU and needs to configure itself for the car again. I was told once that this depends on what sort of driving you do. In my case, the car was used to go from a house to a recycling centre and back, they wouldn't go above 30mph and it was short journeys. My driving takes in long journeys with a mix of 30/40mph zones and motorways. So far the car is still more responsive, the MPG has gotten worse to begin with but has started to improve again.

So what has probably happened here is that your ECU is calibrating/calibrated to deal with the demands you put on the car, compared to the previous owner. But again as Anthony said your gains are short term. Only real way to know if it's done any good or not is put it on a dyno before resetting the ECU and then again afterwards.

[Niklas]

Well, I don't agree with you Michael regarding short term. Could you explain how it can only be short term?
And, if it really is short term, why not do it every fill up then? 
I don't agree on the 'calibrate to my driving' either...would be nice if it could but I can't see how in a resonable way?(Think about it...todays state-of-the-art cars have different driving modes...ECO,Normal,sport.....why don't they have a 'Me' mode then?)

Putting it on a dyno is one way to do it if you need to know absolut power. I know it's more(not by how much) because I drive up the same hill (5th gear, around 2000rpm) several times per week and it can't keep the speed, dropping slowly all the way to the crest. Now, it manages to hold 2000rpm up the whole hill(same conditions, tire pressure, stuff in the car etc etc). Power gain is small, but still. The dyno usually doesn't measure thermal efficency either so it won't tell you if the mpg gone up or down.

ECU systems are so complex that we can only empirically test/measure what works and not. I have measured and tested this 'ECU reset' on my car so thoroughly that I can say it gives better mpg and more power, but not exactly how much. Power is hard to measure(I don't have, or know anyone who have, a dyno), mpg little easier which is why I gave some numbers on it (around 10%). I don't think my car is special in any way so this might work for others also who have the same model/milage and suffer from bad mpg/power. Hopefully, it will be even better when the EGR is fixed  

[mickburkesnr]

Well simply put the ECU that comes out of the factory is generic for the vehicle. The vehicle could spend it's life up in the hills of Patagonia where it's a bit cooler and less oxygen, and another vehicle could spend it's time along the coast of California in the heat and where the air is denser. So in this respect the ECU adapts initially to the parameters it finds itself in. Over time the car works out that, more often than not for example, there isn't as much oxygen around and the temperature is relatively cooler. So because of this it knows to add a bit more fuel in to the mixture to get the best MPG and power possible.

In my experience with this, the first tank full tank of petrol after the ECU reset delivered 320 miles. The fill up prior to the ECU reset delivered the same result. I'm half way through my second fill up since the ECU change, and I think there is a slight improvement. But at the half way stage at the moment I think I'm 5 miles better off? Engine power itself hasn't changed, but the engine response has. And again this is down to driving patterns, demands, environment etc, the fact the previous owner used the car for short journeys when it wasn't up to temperature and drove like a nun.

This ECU reset is always going to be a temporary measure, as I've mentioned above, because you reset it to how it was from the factory when it was built. Overtime you're going to notice the response drop, and MPG go down a bit. But, again, the ECU builds up a picture of the demands placed on the vehicle through environmental factors and driving demands. How your car behaved before the ECU reset will be how it behaves again onces it's calibrated again.

And if it was a magic wand fix for cheap power improvement and MPG improvement, everyone would be doing it ;)

[Anthony Poli]

We are talking about Toyota and not VW, can't fix a mechanical problem with a software fix.

[mickburkesnr]

Just an update on my own experience with this ECU reset.

On the second tank of fuel it lasted 300 miles, a full 20 miles less than what it did before I reset the ECU.

[bbrowne_iQ]

Just basic maintenance, check air filters, tyre pressures and ensure you aren't carrying around any unnecessary weight I guess.