WOW 29.75mpg World record!!!

[Dom B]

Well ok it's not even a club record lol, but for my car it's amazing. In the whole history of filling the car brim to brim, i have never had better than 25.5mpg in any tank. It never seemed to matter if i was cruising on motorways or mixed driving with a thrash here and there as the situation demanded. But the normal 90% of the time average was 22-24mpg

I usually drive at 75-78mph on the gps which reads over 80 on the clocks and this time the only difference i made was to drive at 70mph on a 180 mile round trip. There were a couple of days of mixed driving afterwards and when i filled up i calculated 29.75mpg which is a huge gain. I knew it was going to be better when the gauge was a fair bit higher for the same mileage but i didn't know until i did the brim to brim numbers.

So i guess 68-70mph is just far enough off boost, just that little lower rpm and that little less wind resistance to make it possible.

Maybe 40mpg is possible with the same power and a little low end lean burn.

Don't get me wrong i know as much as anyone that fuel+air =power and when you thrash it she will drink, but the bit that always gets me is there is no reason to drink when just cruising, that's eating up precious thrashing fuel!!

[foxdie]

Bloody hell, I thought the 261 miles I just got out of 50 litres (23.4MPG) was good

[Kitty's VR4]

Gee, this might be a little painful, data logging the reflashed MH7203 today, enhanced fuel/spark maps have yielded gains in fuel economy, maybe the fuel in Oz is a little better in Quality, using BP Ultimate RON98..... sit down boys....
did 445.3k using 34.2litre or 7.68L/100k or 13.02K/L (sit down now) or 36.7MPG............ my previous best was 8.36L/100k from an unflashed MH7203..... 100% highway cycle @ 100-110kph.

Just incase "Knock Values" nothing over 1, excuse me if I grin

[Dom B]

Wow that is good, i'm sure with a little remapping i can get better. But i'm pretty impressed with my figure on stock engine map.

As for fuel quality i run it on Tesco green energy super 99RON, but i believe you guys on the other side of the world use a slightly different octane rating system meaning the octane figures are a little different from ours.

36.7mpg though. WOW!! Good work.

[Davezj]

Gee, this might be a little painful, data logging the reflashed MH7203 today, enhanced fuel/spark maps have yielded gains in fuel economy, maybe the fuel in Oz is a little better in Quality, using BP Ultimate RON98..... sit down boys....
did 445.3k using 34.2litre or 7.68L/100k or 13.02K/L (sit down now) or 36.7MPG............ my previous best was 8.36L/100k from an unflashed MH7203..... 100% highway cycle @ 100-110kph.

Just incase "Knock Values" nothing over 1, excuse me if I grin

Ok Kitty, spill the beans what have you changed in the maps or did someone else do the mapping.

Great result though, my best at 70mph was 32mpg. but that should get better at 62mph (100Kph). however i have never been able to drive that slow on a motorway for any length of time to prove it. 140miles at 70mph was hard enough i had to be so careful to keep it off boost, it was some of the hardest driving i have ever done, the consentration required was imense. It was done on relitivly flat roads as well manchester to warwirck way on the M6, M5, M42, M40.

[Kitty's VR4]

LOL, Not giving to much away at this point, early days yet, basically changed the fuel maps, added extra spark maps, changed the timing by a few deg in the 2100rpm-3200rpm range, tuned to run on our 98RON fuel and a few extra bits and pieces, no boost changes on this particular ecu at this point. These are more courtesy post's to let you guys know the MH7203 is now flashable with the beta version of ecuflash...... So it's time for you guys in the mother country to extract your digits and play catch up with the convicts, just as we are having to play catch up with the MH7201 ECU reflash !!

The 100% highway figure relate to my previous figures 8.36L/100K, todays figures where with a bit of everything, highway, bumper to bumper in Sydney traffic, some mountain twisties. The elevation was from just under 900metres, down to about 20metres above sea level and back home to the 800metre elevation.. oh and a blat to test that speed limiter changes worked.

Tomorrow I'll be doing a 200km run to canberra and back that will be 100% highway cycle, I'll post the figures up tomorrow night in case you interested.

[SGHOM]

All the above is a load of borrox.

Truer mpg should be monitored over a period of weeks or months, not on one trip..... Long or short.

I have the benefit of a trip computer in my saaaab, & believe me.... I'm like driving miss daisy nowadays .... Ferrying old folk around!

I've not reset it since Easter, & I'm currently getting 20.1 mpg. & that from a 2.0 ltr lpt.

This begs the question ....... Can a trip computer be retro fitted ??

[Kitty's VR4]

Actually Derek, thats fairly true, I have records for the 9,000k I've travelled since owning the VR4, averaged figure is 9.87L/100k. Todays logging exercise wasn't about getting the best fuel economy, it was about logging whats happening across a full set of driving conditions, tomorrow is about economy, but the main thing is that there is noticable improvement in economy.

I just thought you guys would appreciate the heads up.

[Davezj]

all info is good for mapping kitty.

just let us know what you have done to edit your tables and what the startard tables are. we can see if they are close to what we have in our ECU. i am assuming the 7203 will have a newer base map than the 7202 has to begin with then you have changed these to get to where you are now.

should be interesting. i am not able to remap my ecu at the moment but i know a lot of people are and the info will be greatly received .

i know of at least one person that has leaned out the fuel maps across the board and changed the fuel cut table and is running 18psi with no problems and i believe he is monitoring his AFR correctly as well. so it would be interesting to see how yor changes differ from his.

[Kitty's VR4]

There is very little difference between the 7202 and 7203 (some extra spark maps and a few minor tweaks)

When a complete base tune is ready for publication, it will be available on OzVR4, and I'll paste the link here on CVR4, guys don't take this the wrong way but I'd have my throat cut if I did this any other way!!!

You guy's had the march on the MH7201 and I haven't seen that being made publically available !!

If you'd prefer that I pack up my bat and ball and not let you know whats going on then I'll continue paying my membership sit in the corner and shut up!!

[Kieran]

When a complete base tune is ready for publication, it will be available on OzVR4, and I'll paste the link here on CVR4, guys don't take this the wrong way but I'd have my throat cut if I did this any other way!!!

You guy's had the march on the MH7201 and I haven't seen that being made publically available !!

If you'd prefer that I pack up my bat and ball and not let you know whats going on then I'll continue paying my membership sit in the corner and shut up!!

Understand your position, Kat.

And are we having a bad day, perchance?

[ianturbo]

Last year goin to Gt yarmth i got 320 miles out of a tank full ,how to work that out in MPG i aint got a clue but i thought it was good !!
ian

[BraindG]

ive just come back from two trips, to and from glasgow.

223 miles each way, both ways light was on when i arrived at my destination.

i used to get to perth on a full tank

Maybe a service is required, although min speed was 90.

[mattnz]

So the revelation is that going slightly slower will get you better fuel economy? Incredible :/

[phosty]

There is very little difference between the 7202 and 7203 (some extra spark maps and a few minor tweaks)

Do you mean there are more than the twin pair (i.e. 4 total) of Hi/Lo timing maps that the 7202/7201 has (ignoring the cat warmup tables)?

Interesting if so.

[Davezj]

There is very little difference between the 7202 and 7203 (some extra spark maps and a few minor tweaks)

When a complete base tune is ready for publication, it will be available on OzVR4, and I'll paste the link here on CVR4, guys don't take this the wrong way but I'd have my throat cut if I did this any other way!!!

You guy's had the march on the MH7201 and I haven't seen that being made publically available !!

If you'd prefer that I pack up my bat and ball and not let you know whats going on then I'll continue paying my membership sit in the corner and shut up!!

i totally understand this from your point of view. i am just interested. even if you spelled it out to me i probably would not understand it as i am no flasher (pardon the pun).
when your ready to show your hand one way or another i am sure we will all be interested.
i have subscribed to this thread so any little tit bits of info will be mused over with interest.

[Dom B]

So the revelation is that going slightly slower will get you better fuel economy? Incredible :/

Not that simple Mattnz, i also found that going at less than 60mph, the mpg dropped like a stone again as the engine was being either worked harder against 5th gear or was revving more in 4th. 68mph seems to be the sweet spot for my car. Its a trade off between moving at a p;ace to eat up miles but at a speed that doesn't have the air resistance too high or the revs/boost too high all the while trying to stay at the engines design point which on most cars is 2500-3500rpm.

You can get the turbos to boost much earlier under load in a higher gear than you can under little load at a slightly higher speed. You may have noticed that when mapping a car for boost you can't really get any boost by just revving the car when stationary you have to drive it or have it loaded on rollers before the boost gauge will read full figures.

[Dom B]

With all this decoding and re-flashing work going on everywhere i am interested in how people are doing it. Are you desoldering the eerpoms from the boards and reading them in a raw form i.e. a simple binary file then by just trail and error trying to figure out the shape of the memory map and table locations then trying to identify which table is which by a bit of educated guessing. Or are you able to get all the data out of the mut port. Also what software are you using to manipulate the data and reflash it to test it.

[Turbo_Steve]

With all this decoding and re-flashing work going on everywhere i am interested in how people are doing it. Are you desoldering the eerpoms from the boards and reading them in a raw form i.e. a simple binary file then by just trail and error trying to figure out the shape of the memory map and table locations then trying to identify which table is which by a bit of educated guessing. Or are you able to get all the data out of the mut port. Also what software are you using to manipulate the data and reflash it to test it.

Unhelpfully, the answer is "Yes" to all of the above!

[wintertidenz]

The 7201's are flashed by desoldering and resoldering the flash memory onto the boards.
7202 and 7203 are flashed through the MUT port with an OpenScan 2.0 cable and Evoscan. It's then reflashed using EcuFlash.

The maps are read in hex and then an XML file is generated to map out where everything is, there is still a lot left to map for our cars though.