New Chevy Silverado Engines to Use AFM

AFM 5.3L V-8 photo II

Reports are starting to filter out about some of the possible powertrain strategies GM might use for the next-generation Chevy and GMC half-ton pickups, due out next year. 

According to Automotive News, GM engineers are saying they will continue to use the existing (though improved) cylinder-deactivation technology, called Active Fuel Management, currently used on certain V-8 options for the Chevy Silverado and GMC Sierra 1500. We think GM is planning other weight-saving measures and advanced technology solutions to help the new half-tons achieve fuel economy improvements, but probably not to the extent we just saw in the 2013 Ram 1500. 

The GM strategy has been pretty clear from the start: come to the U.S. pickup market with smaller, more fuel-efficient midsize pickups for buyers who need the higher gas mileage, while leaving the more mainstream work-duty full-size trucks for bigger loads and towing. Of course, Ram Truck does not have a small pickup anymore, so it made every attempt to make the new 1500 all about fuel savings, hence the HFE model (18/25 mpg city/highway) requires the start/stop engine technology, low-rolling-resistance tires and a bed tonneau cover — all for $29,195. (It should be noted that Ram does offer the 4x2 V-6 with TorqueFlite 8 suspension in regular, quad and crew-cab configurations with 17/25 mpg.)

It will be interesting to see if GM will includes its best fuel-efficiency technology (AFM-plus?) on one specific model or make it all available across the new lineup. But we do know that the current AFM technology has quite a bit of room to allow for both more aggressive and more programmable settings if the GM engineers want to go that direction. Current AFM technology is reported to offer between 7 and 8 percent improvements compared with non-AFM models, but we could envision a selectable driver-controlled button offering both Eco and Highway settings that could change the computer-mapping programs to bias the system to be more aggressive for around-town driving or long-haul cruising. 

AFM 5.3L V-8 II
No doubt Ford will very interested in how truck customers will view the Ram and GM strategies, but it seems to be doing just fine with the continuing EcoBoost success. In fact, by year's end, Ford is likely to surpass its 250,000th F-150-equipped pickup, making the engine the most popular in its pickup truck lineup across the board. And they're getting a premium price for each one of them. 

Are you listening, GM? We hope you have something up your sleeve because just doing the same old thing — even if it's a little bit better or of a higher quality — may not be enough to attract the attention of new-truck buyers. We'll see. 

For more detailed information on how the AFM system works, download this AFM video

 

Comments

I like the GM and Dodge idea of cyclinder deaviation..I would much prefer over Ford V8 Ecoboost......as it ages I think the afm will be more realible than Fords with all the turbos etc.

sounds like GM will be using the same old gutless engines, AFM is a joke and never talked to one GM owner who was impressed with it

I like the idea that GM feels the full-size trucks are supposed to be able to handle payload and towing. The Colorado is going to be for fuel effeciency and the urban DIY customer.

I have AFM on my 2007 5.3 Sub. It works fine but I'm not necessarily impressed by AFM so much as I'm impressed that it hasn't failed or managed to cause some other problem in the 121k miles I've had the truck!

It's pure gimmick though and certainly not worth paying extra for. If I cared about gas mileage I wouldn't have bought one of the biggest 4x4 V8 trucks you can get. I would have preferred MORE power and less mileage - the 5.3 is pretty darn gutless. My Tundra 5.7 puts it to shame.

@texmln
I always wanted to know what kind of hwy mpg could the 5.7L iforce get if it had AFM? The thing I wish Toyota would give the 5.7L iforce is start/stop tech as I could really use that.

GM, you should have put the 3.6 in the 08 half-ton instead of the 08 Cadillac cts, you guys have simply let Ford get way ahead, so what ever the 2014 pickups are, they are going to have to be really special ???

@charles
Ford doesnt make a Ecoboost V-8, the Ecoboost engine is 3.5L V-6. As for reliability the Ecoboost technology has been around since 2007 there have been no turbo failures. The Turbos are design to out last the engines, using the same technology and engineering of Class A trucks turbo sytems.

I had heard that cyclinder deactivation only works on pushrod engines. I'm not sure if that is true. It would explain why only Ram and GMC has it.

It does seem that GMC isn't going to try to regain the MPG crown with full sized trucks as they keep saying that is what the mid-sized truck is for.

If that is the case, maybe we will see the 7 litre Corvette motor in a pickup.
Chevrolet SS anyone?

GM still sticking with push-rod engine technology in there V-8's, while all of there U.S. market cars have gone to DOHC technology to stay competitive. With this Ford will continue to lead in drivetrain technology, and I can imagine what Ford has planned for the 2013 F150.

I had high hopes for lighter, all-aluminum, DOHC, 32-valve, VVT V8 engines in the new GM half-ton trucks, with maybe an 8-speed automatic and discs all around, but it appears not to be happening. Maybe it's not too late yet.

If this is the best that GM can do for 2014 with their engines, I'll have to omit them from my shopping list when I go shopping in 2014-2015 for a replacement for my 2011 Tundra 5.7.

My friend has a 2011 chevy with afm and says it doesn't work very often. He has the worst setup tho, low hp, 3.08 gears, and 20" wheels. On the other hand, my 2011 ram hemi with 3.92 gears and 20's runs on 4 cyclinders 60% of the time. I believe the combination has to be right for it to work as intended.

One of the best advantage of using turbos with direct injection is the amazing horsepower gains from a after market intake or exhaust. Bullydog has a cool air intake system that increases the horsepower of Ford's F150 Ecoboost 3.5L V-6 From 365 to 398HP and torque form 420 to 455ft/lbs thats a amazing gain of 33.1 HP and 35ft/lb. all while increasing fuel economy.

Ecoboost: Bullydog intake
398Hp
455Ft/lbs

@Lou
I thought it only worked with pushrod engines as well until recently I saw it on this engine http://motoren.wordpress.com/2011/07/22/mercedes-m152-amg-v8-details/. The last time I read the Mercedes 5.5L V8 was a DOHC engine http://www.motortrend.com/roadtests/luxury/112_0804_2009_mercedes_benz_cls_class_first_drive/. I could be wrong maybe someone could shed some light on this.

AFM and Stop start isnt really all that useful. Its something though and every automaker should have it. AFM isnt really all that big of a help because your still an 8 cylinder and you have to counteract the drag of all 8 cylinders. And Stop start isnt all that useful because modern trucks dont use that much fuel at idle anymore. But i guess small things add up.

@Highdesertcat-I am sure that you would not even look at a GM, Ford, or Ram before this article because of your preference for the Tundra, which I myself have no problem with your preference but lets be honest. Since I am not in the market for a truck now and probably never for a full size I withhold any opinions on this engine. I am interested to see the new Colorado.

Most of the bloggers here for the most part have decided their product loyalties and whatever GM does will not change their brand preference. If someone really has a strong brand preference then they are going to choose the brand they like and that is perfectly ok, no one owes an explanation as to what they like. Everyone has a freedom to choose what they like without being criticized.

@Lou-I think they need to go ahead and have a SS version Silverado with the Corvette motor. It is not going to be high volume but there are enough Chevy diehards that will buy this and the good publicity would go a long way to repair some of the damage that has been done to the Chevy name. Chevy SS trucks have always been a winner for Chevrolet.

My '08 GMC w/ 5.3L and AFM runs flawlessly, but I don't see where the mileage is improved any over engines w/o it. I averaged 19 mpg on a recent trip through PA averaging 75mph w/ the a/c on, but don't see this as impressive at all. My friends old '85 chevy 4X4 w/ a 5.0L auto averaged 21.

As far as the 5.3L being gutless... Ask the guy with the Hemi 4X4 that I have smoked a couple times if the 5.3L is gutless!

i have heard afm contributes to oil consumption. i have a 2007 ram 1500 with a hemi and mds does not consume oil. yes mercedes has a cylinder deactivation system. its a wonder if they did not considering they used to own chrysler.

@5.3LOL - thanks for the link. I did a bit of searching and found out that it is used with overhead cam engines. This link explains the system in both OHV and OHC engines:
http://alternativefuels.about.com/od/researchdevelopment/a/cylinderdeact.htm
It is rumoured that GMC will release a 6.2 litre 4 valve OHC engine with cylinder deactivation.
Can you say Hemi 5.7 and Ford Ecoboost killer? That engine would also eat the 6.2 Ford's lunch.
Maybe this technology will find its way into the 7.0 Corvette engine?
If GM has decided that the Colorado is for fuel economy and the 1/2 tons are for serious work/play Ram and Ford (Tundra and Titan) are in for a rude awakening.
It would be nice to see the "Heartbeat of America" come off of life support and get some blood pumping in those sclerosed arteries.

Imagine if they put those R&D dollars behind diesel... We would have the best of both worlds. Oh well. Let's all go pay super premiums for mediocre fuel economy improvements in gas engines instead. Brilliant.

imo cam in block engines are just fine, as long as they are american V8s. what makes gm look stupid is the fact that they have a sorry V6 based still based on the gen II small block but they are one the gen IV small block currently. why not create a gen IV small block at the least (3.6 would be better). ad to the fact that the 4.8, 5.3, 6.0, and 6.2 are all the same motor just with different horespower and mpg ratings and you say what the hell! either go with the 6.2 for horsepower, 5.3 for mpg or get a hemi. the 4.8 suffers from no afm or 6 speed. 6.0 is hybrid only and who wants a truck that isn't capable and problematic or costly to service? chryslers cam in block has risen to be the best providing the best of both worlds power and mpg. but back to chevrolet why have 4 different versions of the same motor just with compromise. stroke a 4.8 to a 5.3, bore a 5.3 to a 5.7 (346 ls1/ls6 gen III V8), bore a 5.7 to a 6.0, bore a 6.0 to a 6.2, and bore and stroke a 6.2 to 7.0. or put a supercharger on a 6.2. the best thing for chevy is to have a 3.6, 3.6 twin turbo maybe, 5.5 gen V, 6.5 gen V maybe, 4.5 duramax maybe, but not 10 different V8s that are all basically the same because that isn't options and it makes cam in block motors look stupid. however a cam in block V8 is staple for hot rodders as well as they can hold there on with comparable OHCers.

Here is the PUTC story on the next gen Chevy 6.2:
http://www.pickuptrucks.com/html/news/gm/uaw/futureunionuaw.html
It also looks like Chevy will use a TTDI engine like what is already in the Cadillac:
http://news.pickuptrucks.com/2011/07/unofficial-details-leak-about-ford-and-gm-next-generation-pickup-truck-engines.html
This link mentions the rumour of a 7.0:
http://news.pickuptrucks.com/2010/02/future-truck-2013-gmc-sierra-1500.html
If these rumours turn out to be true, Ram does not have a hope in hell of gaining #2 spot in the USA.
Ford needs to pay attention to the little warning sticker on the right mirror "objects in the mirror are closer than they appear".
If the next gen Chevy engines are truly spectacular, Ford may loose the #1 sales crown.

@Josh - who learned what from whom? Many North American engines are rather crude lumps compared to what is available in Europe.
Cylinder deactivation is a different animal in an OHC engine as opposed to OHV. I suspect that Chrysler learned that trick from Daimler and not the other way around.

@Jeff S - a Chevy SS "halo" vehicle would be cool. It would draw attention to their own heritage and draw attention away from trucks like the Raptor and RamRunner. For most people a "muscle" truck would be more useful than a desert truck. I think that an Aussie Holden Ute would make a cool "halo" truck. Offer it with a V8, a TTDI, and a baby diesel just to test the waters.

@lou that is what i ment. i was saying they should have cylinder deactivation considering they owned a company that uses it. i know chrysler probably got the tech from mercedes. the pentastar comes from mercedes tech. i am a chrysler nerd but not an annoying troll.

a ute in america would be cool hot rod (the return of the el camino). the corvette is getting a 5.5 gen V V8, which would be good in the trucks to get rid of the 5.3 and 6.2 at the same time. the 5.5 is supposed to be everything the 6.2 is in horsepower with better fuel economy.

@ fear the voices a 5.3 6 speed probably would out run a 345 hp hemi because it has better gearing and gearing counts more as hp gets that close 315 hp vs 345 hp. i doubt a 390 hp though unless you got a 5.3 reg cab short bed 2wd 6 speed 3.42 limited slip vs crew cab short bed 4wd 3.55 hemi. power to weight ratio. i mean i outran a crew cab 4wd had to be 5.3 who knows if it was 4 or 6 speed and what rear end but i out ran him with a 2007 ram 1500 quad cab short bed 2wd 5.7 hemi 545rfe 3.92 9.25" anti-spin. but there are many variables to consider with things like this as trucks are like the original muscle cars. different sizes, different motors, different transmissions, different rear ends limited slip or not. as for the guy that i raced, i am not going to lie, i didn't out run him by much, but i still out ran him.

That's what's wrong with government motors and dodge, they are not running on all cylinders.

Junk tech from a junkie company.

Instead of calling it AFM, why not call it slappy?

@Josh - sorry, I misunderstood what you said. Nice to talk to a "nerd" as opposed to a "troll" ;)
You raise some valuable points. I'd never consider a 4.8 because the 5.3 is superior in every way. I had a Safari van with the 4.3 V6. It was okay but my 5.4 F150 crewcab beats it for mpg. GMC does need a huge revamp of their lineup. The most persistent rumours are for the new Cadillac TTDI V6 to find its way into the 1/2 tons. The 5.3 is rumoured to stay but in name only. It is supposed to be truly "all new". I bet that means DOHC. I suspect that a premium 6.2 is more likely than a 7.0. They probably will use a normally aspirated V6 as the base engine.

@lou i doubt OHC for gm as they would not call it gen V V8 and car and driver already said gm's corvette was going to have pushrods. i mean i honestly don't know just a good guess though. i was a gm fan long before a chrysler fan. i was raised on gm trucks and as a result know more than i want to. i took a look at chrysler considered them because they were a different american company and not ford. my dad had a ford ranger that burned up in our yard and almost caught the house on fire lol. the firefighters got there just in time as it burned half way through the truck and almost to the gas tank.

My wife's 6.0L in her G8 GT has AFM. It is pretty seamless--although at idle, you can feel the car "rock" a little from time to time.

My biggest complaint is the TERRIBLE transmission programming. It is like GM is scared that the trans will break if you decide you need to accelerate.

It is sad that my Tundra trans shifts like a rattlesnake and my sports sedan like a sloth.

I assume the Silverados/Sierra shift similarly, but perhaps that helps explain the EPA rating.

eventually V8s might die out, but for now they are here. they might sell a lot, but mainly in high trims. so why offer more than 2 V8s for a truck. other engine options with less cylinders, or different fuel type or both gives better options to add to the list besides 3 other versions of the same motor. chrysler is on a roll. ford is too but need to simplify a little more which will probably happen like this. ford will probably in the future have a 3.7 DI, 3.7 DITT to replace the 3.5 DITT, a 5.0 DI and a 5.0 DI TT to replace the 6.2. even though i don't consider ford a company that i would ever buy from, you have to admit they have something with the 5.0. 444 hp from a boss 302 8500 rpm?! wow! from a small (not supposed to produce this much hp!) to V8 (not normally associated with these rpms). i was reading hot rod magazine on my lunch break and comp cams said it is so easy to squeeze 500 hp out of a 5.0 that it is funny. that is 100 hp per liter. very efficient.

so what i am saying is if you can have 5.0, or a hemi, why have one of gms v8s. hopefully gm will catch up with the times because even though i will never buy from them again, it is good to see good competition.

@anyone who asks about the comment 2 comments back - gms chevrolet small block is supposed to be some "divinity". they will keep the same bore spacing, cam in block, pushrods, etc. so considering the gen V moniker, it will have all this. i just hope they don't give them the same ci and liters as the current v8s as confusion would arise to some extent.

most of all is the question of the future of the hemi. will it go direct injection? if so how considering 2 plugs per cylinder? will its replacement have DOHC considering fiat? or will heritage be something for chrysler as well (like chevy small blocks)?

@josh - I see your point as Gen V does suggest evolution not revolution. There was a story a while back about cam in cam technology as a way for GM to stick with pushrod technology. It seems to be an overly complex way to stay with their traditional engine layout.
You mention the Boss 302 and 444 hp. It is interesting in that Ford supplies the customer with a second "key". You stick that key in the ignition and the computer nannies increase power to that 444 hp level.
European cars have had that kind of technology for a while. You change settings for suspension, shift points, and peak hp.
We should have that kind of tec for pickups. Ram's air ride is a step in that direction. Why not do that for power. Tuner kits for diesels do the same thing. You get an economy setting, standard setting, tow/haul setting and race settings.
Companies sticking with tradition may inadvertently fall behind. In theory Chevy could run into a technological wall with pushrods. As you pointed out, the 5.7 2 sparkplug architecture could also limit further evolution of that motor.
Fiat does have the technology for some truly stellar engines. Ferrari comes to mind. That kind of tec might eventually trickle down. Price would be the limiter. A super high tec engine in a million dollar car sells, but that same engine can't go into a mass produced vehicle as it would cost more than the product it was inserted into.

It would be nice to see Chevy get back into the game. If Chevy ups the stakes then Ram and Ford will up the stakes as well. This would make it better for everyone. We would hear from the Bobs again bragging that Chevy is best but we are use to the Ford and Ram fanboys. Competition is good for everyone.

@Josh--I am not the expert on motors but it appears that you know a lot about them. Growing up my parents had a 64 Impala wagon with a 327 cu in 4 barrell Rochester carb that had 250 hp which was great but nothing like what they have today. My older brother had a 64 Dodge Polaris with a 440 which was awesome. I had a 73 Chevelle with a 350 2 barrell that ran like a 4 barrell (it was quick). I am more familiar with GMs and Mopars. I don't have as much knowledge about Fords except the 351 Cleveland and 289 which I know really date me. I will respect your judgement and Lou you know a lot as well.

I hope with all the suspense going on about the 2014 GM twin trucks that it is not a let down and that they come up with something spectacular because there are a lot of people out there waiting for something great. GM cannot afford to disappoint.

As a true blue Ford man, put a gun to my head and force me to choose an engine that absolutely Cannot fail or my family will all die, I will Without hesitation pick the V8 Chevrolet engine anyday over anything else available in the enitre world. For me, that says a Lot! Get rid if the damn piston slap and there's nothing wrong with what they have right now in the Generation 3-4 (LS Series) of SmallBlock Chevrolet's. Although I wish they'd just quit being trendy and call the 5.3 a 327, make a 350 and call the 6.2 a 383. Hell, they do that cool stuff for the 7L Corvette in calling it the 427. Maybe even do a 454.. For me, it's the piston slap that completely ruins them and their reputation. I do however look forward to the 5th generation of the mighty Smallblock Chevrolet.

The trucks themselves however is where it all goes to hell. Exteriors, interiors, quality & durability, body designs, frame coatings, suspensions, brakes, build quality period, working man options, high end luxury options, on and on and on it goes. We've covered this stuff a zillion times here and it's discussed to no end all over the net and in real life. For Engines though, This Ford man will take a Chevrolet anyday. Provided it doesn't have piston slap that is... Cam in blcok designs are newer than the cam over valve design for those who enjoy to argue such things by the way... It's simpler and more compact. Ford should have stayed with the REAL 302 IMO. I've Never had a Modular motor fail but I still can't say I'm in love with them. It's everything else about the Ford trucks that makes me love them. The engines are just kind of "there".. Unfortunately (and I truly mean this), they just don't have the soul of the Chevrolet V8's for whatever cosmic reason..

When Ford brought out its new engines, Chevy boys were criticizing them for not being "proven," I suspect that argument is going to change to "Chevy is newer and better?"

These are the conversations we need to have on a regular basis on this site. Fans of varioius brands talking about the pro's and cons of trucks and their engines. This is how we all learn and grow. Bashing justs ruins the site and kills intelligent discussions. It sucks to have to read 100 posts to find 1 gem among the rough.

@FordTrucks1

Besides piston slap, GM's Gen III and Gen IV aluminum block engines also have an issue with block porosity and the rear main seal (as per a TSB issued by GM).

My 5.3L truck had this issue and developed a pretty severe oil leak around 55,000 miles, at which point the rear main seal had to be replaced. Luckily it was under warranty, but if it wasn't it would have been an over $2,000 repair.

I've also had issues with surging at idle, which turned out to be a symptom of a dirty throttle body (which I fix by cleaning the throttle body whenever I clean or change the air filter).

GM's small blocks have a reputation for being dependable, but I've actually has better luck with both my Ford 4.6L and Dodge 5.9L Magnum. I really think it comes down to individual engines rather than blanket statements on engine reliability. You never know how reliable it's gonna be until after you've driven the heck out of it.

It seems GM has been very tight lipped about what might come out of engineering powertrain in MI.

Jeff S | Aug 27, 2012 6:15:12 PM, that's not true. I've owned several USED trucks from all the manufacturers, but I've only owned ONE NEW Silverado and ONE NEW F150.

And every time I shop for a NEW vehicle I actually LOOK at everything that is available in that class at that time.

That's the way it was when we retired my wife's Towncar. We LOOKED at Acadia, Enclave, Explorer but found the 2008 Highlander to beat them all in that class. The Grand Cherokee in 2008 wasn't even a player.

But in 2011, we chose a 2012 Grand Cherokee because it actually beat the Highlander and everything else out there. I kept the Highlander because it still hasn't had any problems. When it breaks, I'll throw it out.

And in 2010 I looked at all trucks including the Titan. The Tundra 5.7 clearly was head and shoulders above all of them, and that's why I ordered a 2011 Tundra.

I check things out for myself before I put my money where my mouth is. If a Ford, Chevy or RAM is better than what I got now, they've each got an equal chance of getting my money when I shop again in 2014/2015.

Ok everybody stop for just one second... Everybody is being polite, I think hell just froze over! Actually this is a great conversation. Thanks everybody.

Good to know that AFM will continue, it is a true winner and outshines other engine fuel management systems. Having used one in a Suburban and gotten 24 mpg on the highway in one of these GM vehicles, it bests anything the competition has. At least one manufacturer is high tech while ford sticks with low tech and Ram copies GM's sucesses.

What I'm finding interesting is the differing strategies being used by the Big Three in addressing the mpg issues. This is great. All you need now is the Japanese branded pickups use something different and you guys will start to have some better choices.

I hope all pickups evolve into better vehicles for the future.

@Highdesertcat-I apologize for the stereotype. I just assumed from reading your prior blogs that once you got a Tundra nothing else would do. I know that you have had Chevys and Fords before. I was not trying to upset you. I have no problem with those that have brand preferences, my problem is with fanboys of any brand.

It does no good to tear a brand down and as for GM as a taxpayer who is invested in GM and as a supporter of the middle class worker I want them to succeed. From most of the comments I am reading here even from those who are not GM fans I am seeing that most of you as well want to see GM succeed and hopefully learn from their past mistakes. I want to see Ford and Chrysler continue to prosper even if I decide to choose another brand because of my size preferences in trucks. We have lost too many industries in the USA and we will probably lose more so why don't we give support to all our industries and to any foreign corporation that puts plants in NA and hires NA workers. I get so angry at some of they fanboys negative comments and when the belittle others. I don't like it when someone tears me down or tells me why opinions and choices are not important. I don't want some fanboy to tell me that driving a midsize or compact truck is stupid and that I should just shut up and buy a Ford or a Ram. It anything that drives me to want a Toyota or a Nissan. Tell me what does that accomplish?

This has nothing on the RAM.

GUTS
GLORY
TAKING OVER THE WORLD
RAM

you know Jeff s if i didn't know better i would sat you are a GM/Chevy fanboy you are always defending them, i like the options i have in 1/2 ton trucks, but make no mistake about it GM/Chevy is not an option for me for about another 5 years what they have now is old and out dated, now they are coming out with new engines i will be waiting awhile

If this is what GM is coming up with, then GM needs a new executive board with guts-- I don't drive a GM anymore, but I did for about 25 years. I honestly was hoping to see them buck the trend and drop a 4 cyl. diesel in a half ton. Ford spent a whole of of money on the ecoboost and it's paying off and RAM is quickly introducing some new technology in their truck line. GM's utter lack of leadership will reduce it's pickup truck market share, guaranteed.

@Built with out taxpayers $$$$--You are entitled to your own opinions but I have stated in the past that I would support Ford in the same situation. My support is for the American worker who is our middle class and not for corporations or CEOs. If GM went away I could live with another brand. If Ford or Chrysler went away could you live with another brand? Maybe we should have given more money to the banks and financial institutions? Maybe you would prefer that. It is make or break for GM and it is now up to them. As for any future support I vote Nada. You sound like a Tea Party member. I guess we could just eliminate all the middle class and have a ruling elite? No I am not a fanboy of any kind and maybe I should be more self serving and buy cheap Chinese goods. After all I don't have any children and I might as well enjoy life. Why should I care about the future generations if their own parents don't care. I am getting close to retirement so who cares. Maybe you children and children's children should go work in a sweat shop. The issues are much deeper than GM but if you prefer to have tunnel vision that is your choice.

Parasitic friction losses of a DOHC V8 are substantial, versus roller lifter push rods. Was hoping next generation GM small block would figure a way to get 3/4 valves per cylinder with push rods, or go to electro-hydraulic valve actuation.

GM's early AFM has encountered some excessive oil consumption problems. Seems to work okay on our 2011 Avalanche.

I have AFM on my truck and have no complains whatsoever. The system works seamlessly on my truck.
Good to note that it only works in 2WD. Once you put the drivetrain in AUTO or 4x4 the AFM is automatically turned off.
On my last fishing trip I did 21.8 mpg average. That's on a little over 500 miles sample. About 440 of those were highway miles.
I have a 09 Silverado, CrewCab 5.3L, Z71.


The family of Vortec engines is the most reliable and SIMPLE truck engine today. I am glad to see that they will be continuing the same trend with some major improvements. It is also good to see that they aren't going the EGOBOOST route like their absent minded cross town rivals.

I have a 2009 Chevy 5.3 with AFM and I hope the new version of AFM is indeed more aggressive and/or customizable. As it's currently engineered, when operating in AFM mode, the engine doesn't put out enough power to maintain highway speeds unless you're on a slight downgrade. It's almost like the economy gearing and the AFM are working against each other. If the engine was putting out a little more power in AFM mode, or the truck was more aerodynamic, or lighter... etc.. I think being able to run on level ground at highway speeds using AFM would dramatically increase mileage.



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