Lean Cruise
 

I'm in the market for tuning software to tune my soon-to-be turbo '01 Silverado with a T56. I'm split between EFILive and HPTuners.

Because I am also concerned about fuel economy out of boost I like idea of the lean cruise feature. I commute to work on the highway almost everyday. From what I can tell, EFILive has the capability for lean tune while HPTuners does not. This caused my initial draw to EFILive. But HPtuners seems to have better support online and more users, and is cheaper. If I can squeeze out a couple mpg's then the additional cost is worth it IMO.

Can HPTuners do a lean cruise-like feature by leaning out the fuel table in the cruise region? Are there other any major differences between the two in terms of features?

I've also been through some stock GMT800 and F-body tunes in the EFILive demo and love it. I understand most of the settings. But the timing and VE tables are a little overwhelming. Haven't tried HPTuners yet.

Any suggestions are welcome.

I like and use hptuners. The softwares are equally capable IMO, it just comes down to taste.

In hpt you can run open loop and set the commanded afr to whatever you want, but being open loop you dont have o2 feedback to control fueling, but if your maf and ve tables are spot on you shouldnt need it.

Thanks for the input. How does lean cruise work if the truck is in closed loop?

It doesnt. The o2 sensors will always want to pull it back to stoich, and o2s are not accurate anywhere else anyway. There is a setting for the o2 sensor switching voltage but it does not appear to have any effect.

So how does the lean cruise work then?

"lean cruise" is a part of the operating system that is disabled in the USA. You can edit the OS with a hex editor to re-enable it, and before the US threatened to nuke New Zealand, the EFI guys would tell you what line number to change to a no-op.

However, with the custom OSs you can just set your AFR table to run lean in the cruise cells (e.g. map x rpm areas where you normally cruise at)

You mean since New Zealand banned Mike Tyson?? That's what they get!

So with HPTuners and a custom OS, I can basically achieve the same thing as lean cruise by turning up the target AFR in the cruise region?

My other question would be, how is "lean cruise" in EFILive different than just adjusting the AFR table? Sounds like it may be more of a on/off switch if parameters are met rather than a table that's interpolated.

I just run Open Loop Speed Density and command whatever AFR i want at what RPM vs MAP.. poor mans lean cruise.
Dail in the fuel table and ride.

You dont need even need a custom OS to do it in hptuners. Simply set the closed loop enable temp to something like 280 and change the commanded equivalence ratio in the open loop fueling table.