Its not always about MPG

[Tahoe_Hybrid]

Originally Posted by aerohead

I ran back-of-the-envelope numbers on the Tahoe.If,without hypermiling,you're currently experiencing 31.2-mpg @ 60-mph,in order to achieve 40-mpg,under identical conditions,would require a drag reduction to Cd 0.136,lower than the GM Sunraycer,solar race car of 1987.A 60% drag reduction (if we presume Sunraycer's current Cd is adjusted for a crosswind-averaged coefficient.
The 'baby' template model registered Cd 0.1201 @ zero-yaw with complete canoe fairings on all wheels.
There's no 'physics' boundary obstructing your achieving the new target,however the man-hours necessary for fabrication might blow your 'human-capital' budget all to ---l.

40-48MPG(shown on the read out display) at 45mph steady speed assuming flat grade MPH at 1,000-1050RPM in v4 mode
the issue is it's very very hard to keep it in the EVT mode that is where the mileage is at. and that is my typical speed locally per the speed limit..

just a slight breeze kicks you out of the Eco zone(such as an oncoming car or truck)

that is why i think a few aero mods can KEEP in the in Eco zone




the on the route i take i get 42MPG on the down hill side and 22mpg on the uphill side.(same route both directions) that is how i was able to get the 31.2mpg

variable speeds upto 90mph (just on the downhill sides on the way back up the hill i noticed i was able to save much more gas then going 55 up the hills as the instant gauge would drop to about 9mpg to 13mpg at 55mph )


also i noticed by the time i crested the hill i was going 60mph anyways.. using a light amount of gas pressing to keep the mpg gauge steady at 24-25 instant gauge. to keep the momentum going ..

[Ecky]

Sounds like at that RPM you're not using the fixed gears, but using the CVT ratios.

Nice thing about domestics (or non-Euro vehicles really) is that parts are cheap, eh?

[aerohead]

Originally Posted by Tahoe_Hybrid

40-48MPG(shown on the read out display) at 45mph steady speed assuming flat grade MPH at 1,000-1050RPM in v4 mode
the issue is it's very very hard to keep it in the EVT mode that is where the mileage is at. and that is my typical speed locally per the speed limit..

just a slight breeze kicks you out of the Eco zone(such as an oncoming car or truck)

that is why i think a few aero mods can KEEP in the in Eco zone




the on the route i take i get 42MPG on the down hill side and 22mpg on the uphill side.(same route both directions) that is how i was able to get the 31.2mpg

variable speeds upto 90mph (just on the downhill sides on the way back up the hill i noticed i was able to save much more gas then going 55 up the hills as the instant gauge would drop to about 9mpg to 13mpg at 55mph )


also i noticed by the time i crested the hill i was going 60mph anyways.. using a light amount of gas pressing to keep the mpg gauge steady at 24-25 instant gauge. to keep the momentum going ..

Your specific driving cycle falls outside anything common metrics can account for.It's impossible to design for all the variables you've included.It's hard enough with calm,level,dry,straight,constant speed.

[ksa8907]

Originally Posted by Tahoe_Hybrid

I was able to run it at 1850rpm at about 85mph in v4 mode too bad it's goved to 95MPH..


my IAT/MAF is malfunctioning... I was recording a intake temp of 80degrees when it was 57F on a stone cold dead start (Engine was not running right funky idle ) today it was the correct temp, so that pretty much rules it's faulty IAT/MAF combo....

Be aware, these engines do have cams that incorporate LIVC late intake valve closing. I.E., some air that enters the cylinder will be pushed back into the intake.

Also, definitely not governed to 95mph..... These vehicles are a little slow to clear 60mph but above that they really stretch their legs easily!

[oil pan 4]

So IF you can get up to speed and drive on level ground with out a head wind you can get 40 to 48mpg.
That's about like saying I can make our hybrid car get 100mpg because I see the mpg display go up near that high under just the right conditions.
Neither vehicle will get any where near that fantasy mpg with out major fundamental changes to the vehicle, such as adding a bigger traction battery and charging it with grid power, major aero mods, ect.

[Tahoe_Hybrid]

Originally Posted by oil pan 4

So IF you can get up to speed and drive on level ground with out a head wind you can get 40 to 48mpg.
That's about like saying I can make our hybrid car get 100mpg because I see the mpg display go up near that high under just the right conditions.
Neither vehicle will get any where near that fantasy mpg with out major fundamental changes to the vehicle, such as adding a bigger traction battery and charging it with grid power, major aero mods, ect.

it's pretty steady at that speed... unless it drops to v8 to recharge the vacuum.. but it will go back to v4 mode quickly with in a couple of seconds

[Tahoe_Hybrid]

Originally Posted by ksa8907

Be aware, these engines do have cams that incorporate LIVC late intake valve closing. I.E., some air that enters the cylinder will be pushed back into the intake.

Also, definitely not governed to 95mph..... These vehicles are a little slow to clear 60mph but above that they really stretch their legs easily!

it's governed at 95mph from what i had read. but it could be 137mph

142 mph is the potential over the normal model due to the increased amount power this has over the 5.3

unless you have the NYPD police special.

[Tahoe_Hybrid]

I gotta replace the MAF/IAT as it's broken it's giving fake news to the ECM

causing abnormal running idle (Auto stop not working or idle speeds funky transmission shifts and AFM issues)

[oil pan 4]

Originally Posted by Tahoe_Hybrid

it's pretty steady at that speed... unless it drops to v8 to recharge the vacuum.. but it will go back to v4 mode quickly with in a couple of seconds

Use a vacuum pump to keep the vacuum high, not 4 more cylinders.
Sounds like an easy mod.

[Tahoe_Hybrid]

Originally Posted by oil pan 4

Use a vacuum pump to keep the vacuum high, not 4 more cylinders.
Sounds like an easy mod.

let me get the new IAT/MAF first

i took it out today it ran good even EV mode was running to 30mph i have not been able to do that in awhile

or permanently delete the 4 cylinders... but it's california they hate some eco mods it would fail smog test