V4 vs. V8

[tbrend]

Is Chevy planning on an upgrade to manually switch to V4 when cruising down the highway?

Does anyone offer an aftermarket switch to do this?

 

[Mad Dawg]

Why???? The system (Active Fuel Management) works perfectly and is so seamless, meant to optimize fuel economuy, I believe that it would do a far better job than any of us manually switching between V4 and V8.

 

[tbrend]

It seems like it only kicks in when going down hill.

I would gladly sacrifice power on the road to better mpg. (As long as I can control it)

 

[AZSCTACO]

...but if you were to drive in V4 most of the time then wouldn't you think that only 4 cyl would have to work extra hard to push along our heavy rides....which in turn would get horrible gas mileage. IMO...makes no sense.

 

[Rollin Thunder]

...but if you were to drive in V4 most of the time then wouldn't you think that only 4 cyl would have to work extra hard to push along our heavy rides....which in turn would get horrible gas mileage. IMO...makes no sense.

i actully think the V4 is useless as it runs in v-8 to much. once your on the highway im sure the v-4 mode makes plenty of power to keep it going. even on hills. just as long as your moving. makes sense to me.

 

[georgiawj]

I doubt they will ever let it be controlled manually. It would be abused or too complicated for some people thinking they could just leave it in v4 and always get better mpg.

I wish they would just reprogram the software so it would stay on with just a little more throttle..

 

[nvcaman]

Part of the problem is the sensitivity of the gas pedal. My suggestion is that you turn on cruise control and the engine will generally stay in V4 mode unless you start to go uphill.

 

[LAP TOP GAMER]

V4 would not work in a 5000LB vehicle and I honestly wonder how effective the active management is I have it and I watch the instant mileage no matter how light on the gas you are, as soon as you hit a hill or touch the pedal it drops to 8 MPG:skep: so the only way I see any savings is on a flat road with cruise control on, in city driving, forget it!, don't even bother looking at the thing, I cant get above 13MPG average driving in city. I forget what my gearing is that can have a lot to do with it as well.

 

[georgiawj]

Ya i tried cruise control one time but there are so many hills around here it is useless. It says im getting 19.8 right now though even with very little v4 time (this was with hardly any city driving though mostly 45-55 on hilly back roads)

 

[fco_gonzo]

Ya i tried cruise control one time but there are so many hills around here it is useless. It says im getting 19.8 right now though even with very little v4 time (this was with hardly any city driving though mostly 45-55 on hilly back roads)

You got any pictures of your "cop magnet"? the 81-87 chevy pickups are my favorite.

 

[73shark]

Around town I've noticed that trailer mode keeps it in V4 mode more since it unlocks the torque convertor at lower speeds which increases rpms. I've got 3.73 gears. That might not work w/ 4.10s as I've heard that they stay in V4 more cuz engine is in its "sweet spot" more.

 

[georgiawj]

You got any pictures of your "cop magnet"? the 81-87 chevy pickups are my favorite.

Ya let me try and find some. if not ill take a picture tomorrow cause i just washed the pollen off today..

 

[07LTZ4x4]

The cylinder deactivation is a joke. I have a 07 LTZ 4x4 I also have a Grand Cherokee SRT8 with a 6.1 liter 370ci 420hp motor that is getting better gas mileage than my Tahoe.

 

[Black Dog]

...but if you were to drive in V4 most of the time then wouldn't you think that only 4 cyl would have to work extra hard to push along our heavy rides....which in turn would get horrible gas mileage. IMO...makes no sense.

Absolutely right. And not only that, but I can't imagine that it would be healthy for it to have dead cylinders with pistons going along for the ride when it's under load/ acceleration. Would be interesting though if it could do 6 cylinders for light acceleration when already at speed, though.

 

[rOllwitrOger]

i too think it only works when you're going downhill....or if u accelerate and release the pedal. it's wack, at least we still in a tahoe ?

 

[Rollin Thunder]

The cylinder deactivation is a joke. I have a 07 LTZ 4x4 I also have a Grand Cherokee SRT8 with a 6.1 liter 370ci 420hp motor that is getting better gas mileage than my Tahoe.

your comparing apples to oranges, the jeep weighs less and has more power. so of course its gunna get better MPG.

 

[07LTZ4x4]

your comparing apples to oranges, the jeep weighs less and has more power. so of course its gunna get better MPG.

I agree with you but you would think the "cylinder deactivation" would trump that. I am not knocking my Tahoe I love it; I just find the cylinder deactivation a joke in regards to saving gas.

 

[gundog]

Actually the Displacement on Demand (DOD) from my experieince does save you gas even though it seldom goes into the 4 cylinder mode unless their is very little strain on the engine as in going downhill. I have deactivated the DOD in mine and my mpg were negatively impacted I used the Diablo Predator to deactivate the DOD but since it gets better mileage with it on, I will leave it activated. I drive in hilly country so my results may vary from others.

 

[scotto2323]

The cyl. Deactivatation does work seen through my experience. I can get mine to remain in 4cyl mod and maintain speed by stepping very softly on the gas pedal.

This is mostly on level terrain, reading an inst. mpg in the high 20s-30s. If my avg. mpg is dead on balls accuate this leads me to believe that my instant mpg is correct.

I have done both the regular and the light foot driving styles through a few tanks and coasting with the light foot helps out alot.

Do any programmers out their now offer the ability to mess with the Displacement settings?

If we can tweak the settings to remain in 4cyl mode longer, there is no doubt in my mind that I can see 20+mpg suburb driving for myself.

It is a matter of GM programming. Just like anything else they gradually increase mpg for sales.

 

[Gambler]

I don't know about handhelds, but I had a custom tune done and he was able to bump the amount of throttle it takes before switching up. I think he said it is at 12% by default. It may have helped on the highway a little, but not in city.