General Motors may use an advanced cylinder deactivation technology, co-developed with Delphi and Silicon Valley startup Tula Technologies, in its SUVs and V-8 cars to shut down up to six cylinders to maximize fuel economy, Automotive News reported.
According to the automaker, GM in 2012 invested in Tula, which specializes in automotive engineering. The automaker announced in January that it would pursue the advanced cylinder deactivation technology for some of its SUVs, which could improve fuel economy by 15 percent in cars with engines with more than four cylinders.
The system, dubbed Dynamic Skip Fire, keeps the throttle open during operation and controls cylinder firing through a special valve that cuts off oil to the deactivated cylinders’ valve lifters. According to the company, the engine computer changes the deactivated cylinders to avoid vibration or noise.
Leather is better. (photo courtesy: image.automotive.com)
Long time listener, first-time caller. I’m responding to your plea for new Piston Slap questions. I purchased a gently-used 2008 GMC Yukon Denali AWD a couple of months ago. Other than its appetite for fuel, the only negative is that it has 141,000 miles. I believe the previous owner changed the transmission fluid at 100,000 miles (Carfax shows that the transfer case fluid was changed at this point, and I can’t imagine doing that and not doing the transmission). The fluid was relatively clean but I changed out several quarts via the dipstick tube using a fluid extractor after I purchased the vehicle, replacing them with the specified Dexron-VI. I believe the fluid level is correct but it’s difficult to read.
On a recent road trip, the 6-speed automatic (6L80E) transmission stumbled during the 2-3 shift while driving through the mountains and went into a failsafe mode. The check engine light came on. I pulled over, turned the ignition off and on again, and the truck operated normally. The CEL remained on for the next several ignition cycles. When I called OnStar to obtain the fault code, they could not retrieve it because the CEL was no longer on.
General Motors announced Wednesday it would invest $1.4 billion into its Arlington Assembly Plant, which produces SUVs.
The investment will create a new paint shop, body shop and “general assembly area upgrades” for the plant that produces Chevrolet Tahoes and Suburbans, GMC Yukons and Yukon XLs and Cadillac Escalades.
Construction will take three years and plant operations won’t be impacted, GM said.
Own a new Chevrolet or GMC truck? You might be getting a new set of keys.
Until a decade or so, if you wanted a three-row SUV your choices were pretty much limited to body-on-frame offerings, most of which were related to a pickup truck. But now, even GM’s own GMT960s (Enclave, Acadia), provide similar amount of interior space to this Yukon. Furthermore, they are less expensive, more efficient, and easier to drive. It’s possible to argue that the biggest, if not the only, advantage of these body-on-frame V8-powered SUVs is their towing ability.
So why do GM, Ford, Nissan, and Toyota still bother with these dinosaurs?
I’m currently in the market for a 2005 or 2006 Chevy Tahoe Z71 and was wondering about when would be the best time to buy. Before you question the Tahoe, I’m probably one of the only people who can justify one. I live in Colorado and spend almost every weekend in the mountains hauling people and their gear up 4wd trails and snowy roads to trail heads and sleeping in the back.
I figure that given gas prices going up, this summer would probably see the values drop off. I like to do the opposite of everyone else who will be buying fuel efficient vehicles. But then I read an article by Steve that said the used car market is going to be getting worse. I’ve see prices go down some over the last 6 months (been watching the market), but not by much. So does this summer sound good, should I buy now, or wait for the future? (Read More…)
Sajeev and Steve,
I think it’s time to replace my wife’s 2005 Honda Odyssey EX-L. It’s got 48,000 on the clock and has developed a few problems over the years. Power side doors that get wonky on really cold days, a slow leak in the AC system, a leak somewhere around the windshield, and an intermittent airbag light most recently, to name a few. None of these things is that big a deal, but considering that my wife has held a grudge against me for convincing her to buy a minivan in the first place, they are just mounting evidence in her case to replace the Ody.