Seen all the TV Ads? GM claims optional 2014 Silverado/ Sierra EcoTec3 V-8 beats

[Qikbbstang]

 EcoBoost in MPG.   EcoTec3 relies on direct injection, cylinder deactivation and variable-valve timing to achieve EPA estimates of 16 mpg in the city and 23 mpg on the highway.  I have a feeling the higher torque and HP numbers of the EcoBoost Ford don't even start to indicate the benefits of Fords power. 365 Ford horsepower to 355GM, and 420Ford pound-feet of torque compared with 383GM.

 If I recall the EcoBoost has very broad powerbands. Just hard to believe the GM with its pushrod engine can even compare to the high zoot Ford, I mean really cylinder deactivation is something GM did decades ago and it was a flop.   


http://www.forbes.com/sites/dalebuss/2013/04/01/gm-scores-ecoboost-via-higher-mpg-claim-on-new-gmc-sierra/

[WConley]

... I mean really cylinder deactivation is something GM did decades ago and it was a flop.   

Believe it or not, Ford developed that cylinder deactivation system for the 300 straight six (!!)  After initial tests proved unsatisfactory, somebody at Ford managed to hoodwink GM into taking it off their hands :-) 

One of my supervisors at Ford was on that program, and he was still proud of getting one over on The General.

[fastback 427]

Yeah their whole cylinder deactivation will probably be as long lasting as their quad steer option they tried  . Actually one of my buddies drove brand new chev, dodge, and ford half tons. He bought the ford with the 5.0. 22 MPG highway. Plus the new chev looks like the super duty grill bolts right on. Nice try.

[RICK LAKE]

Hi Guys I work for GM and will bing up a few things I know from working on Sierras and other trucks. NOBODY is getting better that 20 mpg here in the northeast. Hook these trucks upto a trailer and all are in the 12-14 mpg running at 65 mph. Take them into the Penna hills and down to 10-12 mpg. I have a 2000 gmc 1 ton. I get between 10-13 mpg all the time. If you live in a flat area the mileage is possible with an egg under the gas pedal. The new truck have a 20% larger frontal area, running tires that are 40-70 pounds apiece. Have also increases the diameter to anywhere to 22" wheels with a 275- 285 width. Roll resistance is higher. Caddie tryed the 8-4 cylinder game back in the early 80's and had limited luck with it. Most people kept the motor in 8 cylinder operation because of waiting for the trans to downshift and very slow acceleration. This has not changed alot today. The computors are faster, but the truck still lugs at highway speeds. The new Dexos oil also sucks and has little to no protection of the internal parts. people are also driving the truck or car to the end of the oil life. We get trucks and cars that come in for lof and have only 2-3 quarts in the oil pan. There is no low oil pressure warning that will save the motor if you are this low. The new oil senders are now switches with the low switch working at 12 psi. No motor will live long at this psi reading. I am sure that both Dodge and Ford have the same problems with oil consumpion. GM has dropped the oil changes to 4,000 miles from 6,000. Mobil 1 is helps but again the oil consumpion is happening. GM runs a 5W-30 oil and Fords running a 5W-20. I am old school and no way would I run the weight oil and towing a rig through the northeast. I am sure the Ford techs have the same problems with motors at Ford too. Few mileage tests are done where? Iowa, Kansas? Flat ground and a great tail wind. Is this with the AC on or off on a hot day of 95f temp. What speed is the test done at? 45-48 mph? It's not 65-75 mph. Rick

[cjshaker]

Rick, good to see you on the forum.
I agree, it's all about marketing. In my opinion, truck technology has come a long way.....backwards! Everything Rick said is true, tests are done in ideal conditions that nobody can replicate in real life. My '68 F250 Highboy gets better mileage than our F250 Super Duty at work. HUGE frontal areas (and STILL less room in the engine compartment than my '68, and the engine is STILL tucked under the cowl where it's impossible to work on!) and excessively high vehicle weight equals bad mileage.

Diesels are getting as good of, if not better, mileage than the gas engines. But I'm not a diesel fan. I can't stand the smell or the noise, but they are the best choice when towing is your main concern.

[fe66comet]

The LS is a strait competitor to the 4.6 as the LS get's 500HP stock with no boost. The 4.6 has to be boosted and is much larger dimentionally than the LS. The first appearance I can recall on GM cylinder deactivation was the drop in O ring sleeved Cadillac V8 in the early nineties. The aluminum cylinder heads bolted down to the modular aluminum block the sleeve was a cast steel part with a pair of O rings on either end. Problem was the different expansion rates and lack of integrity made for a good milkshake machine but a lousy engine. Project scrapped after a huge recall. Then stupid idea two came along, the gas guzzling no power 5 cylinder Avalanche engine, I could go on and on about that engine but if someone offers to give you one RUN DON'T WALK.

[fe66comet]

Diesel won't save you anything around here to run, over a buck a gallon more than gas right now.