2014 chevy Silverado active fuel management

[DanielAcosta]

I can barely noticed the switch between V4 and V8. I had the truck over 90 mph (near Austin where speed limit is 85) over the weekend, and was surprised it switched to V4 mode at that speed. My 2008, rarely if ever went to V4 once you hit over about 70 mph. I drove over 400 miles during this trip and averaged 21.9 miles per gallon.

 

I do have a question about the active fuel management system. When it switches to use 4 cylinders, it is always the same 4 cylinders that shut off?

Yes, it's always the same 4 cylinders. What were the conditions in V4 at 90mph? I'm guessing light throttle going downhill or a tailwind, because I don't think you can hold 90 steady state in V4. Was your entire 400 mile trip getting nearly 22mpg at 90? If so, you have by far the best mileage I have ever heard of. I'm guessing you were more in the 70-75mph range to get that mileage, or else one big tailwind.

[2014 Sporty Shorty]

I have a programmer now and I have had my afm turned off for 3000km. My fuel economy before was 20.8 avg and it's now 18.8. I think my fuel economy went down because of winter gas but overall it's so much better to not have to deal with afm anymore. Come spring time I'll know for sure if it was just winter gas.

[VMaxtastic]

What is the company that makes the units for the ODBII port? I still have my EFI live scanner from my blackbear tune on my '13 6.2, but I'm gonna hold off on doing any tuning on this one for a while.

[tpgdiver]

No, the entire trip was not at 90mph. Only on this one road for about 30 miles each way. Most of the time it was in V4 mode, as it is a level road and I had cruise control on. About 75% of trip was on an interstate road, than country roads for the rest. I normally average around 19-20 mpg back and forth to work, all highway (36 miles each way).

[MikeNH]

What is the company that makes the units for the ODBII port? I still have my EFI live scanner from my blackbear tune on my '13 6.2, but I'm gonna hold off on doing any tuning on this one for a while.

 

Range.

[VMaxtastic]

Range.

Thank you, I'll be picking one of these up for now too I think.

 

Edit: Scratch that... At 200 dollars I may as well just get a mild tune.

[mzodarg]

Thank you, I'll be picking one of these up for now too I think.

 

Edit: Scratch that... At 200 dollars I may as well just get a mild tune.

That's the same thing I thought when I saw the price. May as well get a tune. I would say that describing the Range unit as a Beast is nothing more than misleading.

 

Mike

[TxTruckMan]

$200 for the Range to prevent V4? That's some expensive snake oil! I need to buy their stock.

[pm26]

 

$200 for the Range to prevent V4? That's some expensive snake oil! I need to buy their stock.

Honestly, how much service work can you get done at your local dealer, or how many truck accessories can you buy for $ 200? To me, $ 200 is very reasonable for a well designed product.

[TxTruckMan]

I just think it's a waste as AFM is not a problem. That's why I call it snake oil. YOu're paying more to waste more gas.

[captras]

I have a 2011 Tahoe, 5.3L, 38,000 miles, AFM. Have had no problems with oil consumption.

[KARNUT]

I read a while back in town put it in m5 it will stay v8, I did it works. I don't notice it to much on the highway not too many hills. I am trying to refrain from putting cat back on this one its sweet right now. If I do then I go with a programmer, Im getting old

[VMaxtastic]

I was talking to the guy at the GM accessories desk today. he said that in teh 2014's, GM is watching closely for people that tune their trucks, and they not have a sort of log file for how many times the computer has been flashed. Not sure if he's blowing smoke up my ass, or if it's true. I think I'll get in touch with Justin on this topic. I really don't want to void my warranty.

[tbarn]

tpgdiver, aways the same cylinders. "General Motors Active Fuel Management engine control system has the ability, under certain light load driving conditions, to provide maximum fuel economy by deactivating 4 of the engines 8 cylinders. The engine will normally operate on 8 cylinders in V8 mode during starting, idling, and medium or heavy throttle conditions. When commanded ON, the engine control module (ECM) will direct the active fuel management system and deactivate cylinders 1 and 7 on the left bank and cylinders 4 and 6 on the right bank, forcing V4 mode. Refer to Lubrication Description and Cylinder Deactivation (Active Fuel Management) System Description."

[tpgdiver]

tpgdiver, aways the same cylinders. "General Motors Active Fuel Management engine control system has the ability, under certain light load driving conditions, to provide maximum fuel economy by deactivating 4 of the engines 8 cylinders. The engine will normally operate on 8 cylinders in V8 mode during starting, idling, and medium or heavy throttle conditions. When commanded ON, the engine control module (ECM) will direct the active fuel management system and deactivate cylinders 1 and 7 on the left bank and cylinders 4 and 6 on the right bank, forcing V4 mode. Refer to Lubrication Description and Cylinder Deactivation (Active Fuel Management) System Description."

Thanks for the information.