Hypermiling the Chevy Tahoe 6.0L v8 40MPG! :O
 

Yes it's the Hybrid version

Hitting 39.9MPG in my city

Setting cruse control set to 41MPH...


going from 0 to 30 on electric(which is the MAX before it automatically starts the motor) then getting to 41MPH and setting the cruse control.. is Yielding 39.9MPG in MY city...


I have not done any mods to it


The highway is a different story it's producing 27.8MPG... at 59MPH with cruse control... :snail::snail::snail::snail:

I use 91 Octane Fuel as it keeps 4th gear longer with minimal down shift to 3rd gear on The freeway

I did tailgate a 18 wheeler W/trailer tail was yielding 65Miles per gallon ( the insist gauge was bouncing between 65 and 99 MPG) V4 mode


18 wheelers WITHOUT Trailer-tail yield NO benefit ZERO benefit...

I wonder if you could get a second battery pack from a junkyard and double up the electrical power?

You'd have to hack into the BCM and other computers to make it recognize and use the second battery pack without throwing any codes. That in itself would be pretty complicated. As with most things I'm sure it's possible, but at what cost.

Our 2018 hybrid hyundai sonata will switch over to electric at about 80mph on level ground.
Too bad chevy uses such tiny motors.

Going to do any mods?

120KW total (two 60kw motors 80hp)
the total combined output is 379HP 472 ft-lb Torque :cool:

very tiny electric motors? :rolleyes:

hyundai sonata = 38 kW electric motor

You can't just add everything together to get a total maximum output. Chevrolet's ratings for that drivetrain are 332 hp at 5100 rpm/367 lb-ft at 4100 rpm.

The Sonata weighs almost exactly 1 ton less than the Tahoe hybrid and has less than half the drag area--so there's not much usefulness in comparing motor power directly.

That sucks that the hybrid portion on the Tahoe cuts out at 41mph.
I would rather have a smaller motor that can be used all the time than bigger ones that I can only use in stop and go traffic and in town.
Unless it's being used to deliver mail, there's almost no point.

no it does not it will still run parallel EV is only 29MPH then cuts to mixed mode


Engine is Required to run at 29MPH or in reverse gear or Manual Mode
NEUTRAL can be in auto stop.....


I wish it would kick in at 40-45 that would be ideal.. for my area

in the hybrid graphic it shows the electric motors doing something at higher speeds 80-90mph..(but rarely take it above 70MPH) as not to wear out the transmission planetary gears.


the other thing I hate is I can't go normal speed to get to 30mph

The car is a hybrid, not a plug in hybrid, right? They aren't designed to go extended distances on electricity alone. :)

Remember that any electricity used has to be made up by an increased load on the engine, which is often less efficient that just using that gasoline to power the wheels. ∞ MPG at < 30 MPH in EV mode means reduced economy at higher speeds when the engine has to work harder to recharge the battery.

regen only works from braking or coasting or if you let the engine idle (according to the infotainment screen\)

My take on the Yukon hybrid is it is the best darn stop start system you can get. The vehicle can be driven on electric only for a short distance, very similar to the Prius, but generally runs the engine by 10mph from a stop.

Our Denali is 4wd, doesn't have any of the aero enhancements, and has the 22"wheels. We average about 19-21 mpg but it is still better than the 12/18 rating of the non-hybrid.

If you want better mileage from one of these, just slow down. By far the least efficient aspect is the aerodynamic load.

Welcome! I've always wondered what these (GM SUV/Truck)s get! They can be tempting buys now.

Do you have any mods planned?

Yes but I want to fix the air dam and fender (had some minor damage when i bought it)

that is how I got a 84,000 miles SUV cheap :D


someother guy on yukon forum bought a same hybrid tahoe 4*4 for the same price I paid with 200k miles



the HIGH speed starts EATS serpentine belts quickly through

it was all ready varnished and tearing it self apart after only 5k miles :eek: asit looks pretty new the paint in not even worn off (that shows the part # still)


you can hear the belt slipping upon 1500 RPM start up

glazed crack fray and slip. all of them... there is 5 cracks running all the way around the belt...


ticking time bomb tell it self destructs..

it has not effected cooling performance yet that is the only thing running on the belt system, other wise it's just 4 idlers and a water pump..


i bought a genuine goodyear Gator back NOS :D not the continental one..

Impressive numbers from such a beast! What are your tank averages?

The max power available from the battery is probably 20-30kw. I don't fully understand how the Tahoe's transmission/motors work, but if it's like the Prius, power is sometimes sent electrically from one motor to the other rather than through the transmission mechanically. That, and possibly being overbuilt for longevity, is why the motors are so powerful, not for EV mode.

I believe the limit is 60amps, so around 20kw depending on soc.

Edit: sorry, that's the limit to trigger the engine on.

I have not ran the tank down but i'm planing on a long trip 2,300 miles
so we can get some pretty 100% HIGHWAY numbers...

My goal is to use no more then 65 total gallons of fuel for the trip So i would need to average 35MPG it would cut my fuel costs down to less then $250 cheaper then a round trip plane ticket... I have a lot of my old stuff to pick up so i gotta to minimize my costs......

Which means that you have to brake and/or idle the car (which both waste gas) to charge the battery. Otherwise the battery gets too low and then force charges, which increases fuel consumption.

In a hybrid, regenerative braking basically takes the gas you used to accelerate, and very inefficiently turns that into electricity when you brake. It's a very lossy process that's typically far less efficient than the standard gasoline motor by itself. That's why hybrids don't really get much better mileage for hypermilers, although they do help offset the inefficient driving style of the average driver.

Highway trips are good indicators of fuel economy if you can go through a full tank. I'm sure a lot of us would like to see some at-the-pump calculations to confirm the fuel economy of the Tahoe Hybrid. Some numbers on full tanks with average driving that includes around town driving would be helpful as well. Steady state cruise isn't as good of an indicator of efficiency. For example, I can typically cruise at 120-140 MPG at 35 MPH in my Insight during the summer, but have never gotten a full tank over 100 MPG.

25mpg was my last combined fill up...... it's still way better then the normal 5.3L non hybrid those 5.3L barely see 12-15mpg..

I just hate the fact GM leaves then engine going on down hills


I'll be replacing the air filter as well as it's clogged Just waiting on the part i need (the torx tool to open it)

25 MPG is really good for such a large vehicle.

I wonder if the engine is actually "running" (i.e., consuming gas) or in some sort of DFCO mode like traditional gasoline cars have, where if the RPMs are above a certain number and your foot is off the gas, it cuts off fuel to the injectors while still leaving the engine "on". In that case the resistance of the engine spinning would add some sort of charge to your hybrid battery without actually consuming any gas.

Yes it enters Regeneration Mode...

sure it running Lean since the MAP drops to "normal idle" levels

i'lll be doing a windows up and A/C on (Electric A/C) it draws about 5-6KW it's a industrial compressor 330v 3 phase ..


a lot of places claim it uses more fuel , way more fuel but i don't think so.. they claim more then 25%(at lest the stupid EPA says)

it cycles like the normal one in a house as well I have the temp set to 60F Very high fan level then drop it to low-medium level. once it gets to a comfortable level...(it gets there very fast with in a few min)


plus next week we will be able to see New VS old air filter :thumbup: results...

I believe the engine must run at higher speeds even when not accelerating to run the trans fluid pump.

These engines don't have a lean burn, but the cam is special and allows LIVC, late intake valve closing.

Wait, wait, wait--you need a torx bit to open the engine air filter housing?

I'm having flashbacks to the Chrysler products I've owned, which used a mix of English and metric sizes, and you needed 5 million tools to do anything. Meanwhile, my last two cars--both Japanese--you can literally take apart in their entirety with 6 metric sockets, a Philips head screwdriver, and a pair of needlenose pliers.

[QUOTE=ksa8907;599735]I believe the engine must run at higher speeds even when not accelerating to run the trans fluid pump.

no it has a Aux transmission pump a AUX water pump as well :(
It falls back to mild hybrid if a failure occurred...



I think I found a Active Fuel Management mpg exploit... hack (aka THE hidden "3rd mode"). 2̶ ̶M̶o̶d̶e̶ :D
.


But I can get Regenration.. to kick in and able to accelerate in 4 banger mode the RPM drops to 1,000 RPM in 4 banger ( it vibrates a little though since it's technically speaking it should not be at 1k rpm) in v4 mode .. the minimum RPM for V4 is 1200rpm for it to be stable or it vibrates slightly

this exploit

could be quite promising...AFM exploit



the v4 a (AFM exploit) you can even force a regeneration event while forcing it to accelerate on a down hill while still in v4(important to have more POWER(electrical power) & speed when you get to the next hill to maximize MPG)..


other wise if its normal regeneration and you take foot off the gas, you might I MEAN might gain a few mph in speed...




I suspect this AFM exploit might work great hahah...


Came in at 24MPG With A/C on medium fan. set to 60F..
Computer reading 24.1MPG average.


EPA BOOST huge claims i should have lost 25% OR more fuel economy...

4.00%- total lost at the A/C @ 60F medium fan speed.. it was 85F outside and 90-95F inside (Black SUV)

or if by EPA claims 18.5 mpg which is 25% loss

Yes Security so people don't steal your "used" air filter

Probably closer to:

Security, so owners aren’t tempted to work on their own cars.

35 mpg sounds a little optimistic, but may be possible if you drive slow enough. I did a 5000 mile trip in my V6 accord going usually 65 +-5. I got 41.45 MPG overall.

The new body style 99 trucks didn’t have torx, I don’t know how long they went before switching but I think they were in all the full size for a couple years before the change. Originally they had a combination flat blade and #3 Phillips. Problem was the 2 at the lower end, kinda hard to reach and being angled, didn’t take long before the heads were rounded off bad. So what do you do? you have to push down hard as you turn. Doing this helped a lot of people over tighten those screws and split the air box lid at the screw. Gm knew they were selling too many air box lids, and the torx was part of the redesign. They didn’t just start out being dicks about it, they just started out with one of the most often removed fasteners being hard to access.

My Insight is the same way, except that half the screws on the hybrid battery panel are torx, presumably to discourage the average joe from accessing it readily.

well the GM cars used clips to hold it on and it did just fine..

the HV battery uses standard bolts on it

Sounds like the problem is, if they had designed it thoughtfully in the first place they wouldn't have had to deal with the broken fastener issues.

Switching over from chevron 91 octane to Shell V-Power 91 octane

They claim to have a new formulation
we will see if it "helps or hurts MPG"

Yes it does

it has v4-DFCO (Fuel shut off) you can watch the O2 sensors hit 0.00 to 0.235 volts that means 100%-75% oxygen... you can actually drive in this mode I found a glitch in the computer system to regenerate,DFCO and speed up on the down hills at the same time . even if it's very very slight


No shell anymore they scammed me , I just use Chevron only

the BEST i have gotten was 31MPG so far around town. so far

55.00% increase over the base EPA mpg
138.46% over the base EPA of a normal 6.0L suburban 1500 (same year/front end)

best on the highway is 26.9mpg (variable speeds)
35% increase over the base EPA mpg
92.85% over the base EPA of a normal 6.0L suburban 1500 (same year/front end)


I think we need to move onto Aero mods as i hit the cap of what hypermile can do

There's lots of aero mods you can do. Pick and choose the ones you like.

You would need a wideband to verify, I am very curious however I would still contend it does not have a "lean burn".

got a p0420/430 fuel trim spiked to +34 as well as the short/long term at 900rpm both banks f unky computer issue i'm going to disconnect the battery and resit the connections and clean them

the positive cable is damaged for sure on the battery it was acting funky the engine was acting like it had a vacuum leak reving up and down...

It's not the motors. There are 2 60kW motors in the transmission. It's the tiny NiMH battery pack, They can only get 35k (47hp) out of it. But the torque is good still.

I didn't know this vehicle was turbocharged. :confused:

I don't notice any difference in my Avalon between 85 and 91 R+M/2 octane.

:D definitely not turbocharged. Though it is 10.7:1 with port injection. I can attest, it does operate better on 91+ than 87 octane, particularly when it's above 90°F.

Are you trolling? ...cause you're at 7700 ft altitude, of course you don't notice a difference.

If it runs better with 91 octane with a measily 10.7:1 CR even at sea level, I'd say there's something wrong with atomization more than anything. Either that or it's coked up with carbon.

the engine runs at 2250rpm at 80mph in 6th? gear equivalent [EVT mode]

a downshift to 3rd would be 4500rpm ish

i used a disable chip for AFM btw


at 40mph it's at 1,000-1025rpm.....

see:https://www.youtube.com/watch?v=zNkz...el=punker4real

I don't see why lower octane would cause it to downshift unless it's severly affected by something else.

On the other hand, it kind of defeats the purpose of getting better fuel mileage if you have to pay for premium fuel.

Octane shouldn't be much of a difference at lower engine loads. At lower loads engine timing and power output have more to do with just finding the right ballance. At idle you should be able to advance the timing as much as you want and not cause any detonation.

Where octane is important is at higher engine loads, like when you have the pedal to the metal. But shifting from 4th to 3rd at part load because of using the recommended octane instead of high octane fuel for forced induction engines sounds fishy.