Has anybody experimented or using HP Tuners lean-burn function. I'm curious to see if anybody has seen any real world mpg gains from using the lean out function during closed loop.

Brad

 

If you're talking about the Lean Cruise, our friends at
the EPA say it's illegal so it's disabled on US PCMs.
Though, I think I'd pay cash money to anyone who
could fix that, by mail.

 

Lean burn increases conbustion temps and resulting NOX emissions. I can't see how a "teeny" bit of leanness would contribute to part throttle fuel efficiency - these engies can get 40 MPG if operated in that mode (on level ground, at 72degrees, with a tailwind...blah blah blah)

BTW, what is the purpose of this mode??? Maybe a mode to heat up the cats?

Hey "offshore" (or "off road only") tuners - any comments?

 

On the air/fuel charts I've seen (like this one):



best economy is indicated on the lean side while best
power is on the rich side.

 

Yea, correct, but again it's only a fraction of a time in that mode, and only a smaller fraction of fuel savings, and I wonder if the added heat induced would offset the economy...

 

To the extent that the heat was extracted thermally
rather than mechanically, perhaps. But I've seen posts
from some Aussies who've seen some pretty good gain
in km/l.

Thing is, unlike most MPG enhancements, it's "free" if
the bits are.

 

Well, according to the HP Tuners website it says that you can enable the lean cruise function of the ECM with their software, thus the query. I'm wondering if anybody has tried and according to jimmyblue the ausies are getting some worthwhile gains from it. Again curiousity creaps in...

 

Well, when I asked the answer was about legalities.
I tried enabling it myself but it had no effect. I believe
you would have to have the version that lets you do
OS editing (and that's a whole 'nother plane) to get a
US PCM rigged to allow it, though probably many other
countries just can fill in the tables.

 

lean cruise decrease fuel consumption by quite a reasonable amount. It operates at very light loads ie. when cruising at constant throttle at reasonable speed - eg. on freeway with cruise control engaged.

on Holdens its common to see 17:1 AFR's once lean cruise kicks in.

Only vehicles with platform type 2 (fyi, F-body is 0 and Vette is 1) can use lean cruise, changing platform type affects far more than just lean cruise, hence we don't allow you to change it. eg. in the code there are a lot of hardcoded checks against platform type and changing it will cause many more problems than it solves.

Solution: move to Australia or buy a GTO

Chris...

 

Lean cruise is golden. Yesterday I enabled it after logging 16.5l/100km and today, after 300km, im averaging 14.7l/100km CITY style driving. On the freeway I drop to 9.5-10.5l/100km at 100km/h.

This has just saved me 8l/tank and a healthy $10 per week in fuel.

 

So, if you have a GTO in the U.S. you can enable the feature and reap the benefits? Or for a conversion vehicle, could you just use the computer from a GTO on a F-body or Corvette harness in your car or do you have to find the drivetrain out of a wrecked GTO and use it? If that is all it takes, then it seems pretty straight forward.

 

The US GTO is a different O/S than the Holdens

 

yes but same platform ID as holden....

 

Hello, first I am new here, found you as I was looking into Lean Burn Cruse with the 3 Gen Camaros, found them in the late 90s, at long last I am building my TPI 383 for my 93 Chevy van.

So I had the idea Lean Burn was only available in the 85 to 91 TPI systems on Camaros and Corvettes.

Here you talking 95 and up??

This brings me to a batch of questions: What cars can this be turned on in??

I have a 93 Chevy G20 Van that I am looking into using it TBI PCM to run a TPI, and now wonder if it can have a LEAN Burn setting to turn on, it is a 16186695. I was planing on putting in a 12277165 PCM complete with MAF, but am considering other possibles.

And any chance it might be hidden inside a 03 Ford Crown Vic P71 Ex Cop Car as well??

IS HP Tuners a device or something??

Thanks..

Rich

 

The OP was last here eleven years ago

 

Look at the post dates before you ask questions. That being said, I experimented with lean cruise on an '04 GTO, which to my knowledge was the only vehicle in recent memory that it could be used on. The OS in that pcm still had it enabled, unlike most anything else in the states. The transition between lean cruise and regular stoich seemed a bit clunky, and I did not see a noticeable gain. These results could easily be attributed to my tuning or driving habits, but those were my results.

 

I see that now, I was SO BLOWN away by the idea that any other PCMs other than the 3rd. Gen Camaros had this setting that I just keep reading hoping to learn more.

I have seen a few such talks on a Truck site and as here just enough info to drive me nuts and as here old data and no answers.

I saw a suggestion to get a GTO, but that was not clear why.

I am hoping it is still hidden in a 1993 Chevy Van OBDI PCM.

And more info you can share will be a help.

Rich

 

For OBD 1, you can use the EBL Flash system. I'm running it on my 93 truck and my 68 Caddy. The thirdgen site should have some info also.
Other ECUs from that era may have it, pretty sure the really old 7747 has it. If you are using TunerPro it should be easy to find. It's called Highway Lean Cruise or Hiwy(I think)

 

I have an 04 GTO, it does have lean cruise. For some reason, it'll work fine for a little while and then it starts dumping fuel at cruise (11.8-12.xx afr) and i cant figure out why. I've tried everything i can think of. I retuned it, cat overtemp on and off, made the multiplier 1.0 so if it does activate, it doesnt enrich. I turned off my power enrich. i tried raising the tps %, raising the map threshold. When it goes rich, it'll sometimes go away if it blip the throttle. It will go away once I dip below the disable mph on the lean cruise. Turn lean cruise off, problem goes away. This rich condition counteracts any gain i get from lean cruise.

 

Thats pretty weird. I have had sensors go bad over the years, especially after tuning on rich conditions, since it gums them up faster it seems. When they start getting weird like that without explanation I swap the sensor out. I always have at least 2 laying around. They go for about $80-100 or so, but worth the peace of mind. They don’t last forever, especially after mods.