1991 Nissan 300 Zx Twin Turbo 5 Speed **69,000 Miles** on 2040-cars

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Infiniti's new VC-T changes the rules of small turbocharged engines

The upcoming Infiniti QX50 crossover does not get our pulse racing, no matter how shapely the QX Sport Inspiration concept that previews it may be. No midsize SUV does, to be fair. But it has something special under the hood – the world's first production variable-compression-ratio engine. That means the QX50's 2.0-liter turbo four, which makes 268 horsepower and 288 pound-feet of torque, will have up to 27 percent better fuel economy. Here's how it works. The trend of moving to smaller, turbocharged engines carries with it one big falsehood. Under low load when the turbo isn't needed, these engines are less efficient than an equivalent engine without a turbo because of the low compression ratio the turbo requires. That is, if you never need the extra power, you're wasting fuel. Turbocharged (and supercharged) engines use a lower compression ratio to prevent detonation. When you force extra air in a cylinder and mix it with fuel, it's more likely to prematurely go boom. Lowering the compression ratio prevents this problem, but it's less efficient. Infiniti's VC-T promises the best of both worlds, with a compression ratio that ranges from 8.0:1 for high-power turbo needs to a 14.0:1 ratio for fuel-sipping efficiency. At its heart the VC-T engine is a simple idea, but it's complicated to explain. Consider yourself warned. The photo below from Infiniti serves as a good visual overview. For the truly nerdy, this patent application covers the mechanical concept. Instead of having the pistons connected to the crankshaft, Infiniti's engine has a pivot arm with a connection on each end. One end connects to the piston, the other connects to a second lower shaft, which is controlled by an actuator arm. At any given time the engine's pistons move up and down according to the lobes on the crankshaft. But the actuator arm can change the angle of the pivot arm up and down. That is, the pistons still move in the same motion with the same stroke, but phase the entire stroke up or down. Move the pivot up and there's less room at the top, which means a higher compression ratio. Move the pivot down and the compression ratio goes down, too. As an added bonus, the lower shaft eliminates the need for counter-rotating balance shafts. Infiniti says this system works constantly and can vary the compression ratio to any number between 8:1 and 14:1. It also uses electronic variable valve timing on the intake valves to switch into Atkinson-cycle combustion for greater efficiency.

Chevy Volt 'acceptable,' Nissan Leaf 'poor' in new IIHS safety tests

Ford C-Max Hybrid also scored "acceptable" rating. With US Nissan Leaf sales up almost 30 percent during the first half of the year, the only thing that might be able to stop the battery-electric vehicle is a good, stiff barrier. Unfortunately, thing's aren't always pretty when that happens in the real world, according to new tests from the Insurance Institute for Highway Safety (IIHS). Things with the Chevrolet Volt extended-range plug-in are a little bit rosier, though. The two plug-in vehicles were part of a batch of a dozen vehicles that just went through the IIHS's "small overlap" test, in which the driver's side front corner of the vehicle is crashed into a rigid barrier at 40 miles per hour. Out of the dozen, only the Mini Cooper Countryman was given a "good" rating. Five vehicles, including the Volt and the Ford C-Max Hybrid, were rated "acceptable," two were "marginal" and two, including the Leaf, were "poor." Plug-in vehicles are unique in the crash-test context because of their relatively large battery sizes. In the Volt's case, the driver had a "low risk" of injury, said the IIHS. But the Leaf's crash substantially pushed back the instrument panel and steering column, creating a scenario where the driver was "likely" to sustain leg injuries. The batteries in both the Leaf and the Volt passed safety tests specifically targeted at things like thermo and electrical properties and overall integrity. "Nissan is proud of the Leaf's 'Good' rating in all other IIHS tests, a 4-star NCAP rating from NHTSA and its IIHS Top Safety Pick rating in all previous years since the car's release," the company said in an e-mail sent to AutoblogGreen. "As for the performance of the 2014 Leaf in the 'small overlap frontal test,' Nissan will continue to review these and other results from the IIHS 'small overlap frontal test' as we seek opportunities for improvement." Check out the IIHS's press release and small car crash-test video footage below. Range of ratings: Small car ratings run the gamut in challenging small overlap front test The Mini Cooper Countryman is the only small car to earn a good rating among the latest group of 12 cars subjected to the Institute's small overlap front crash test. Two electric models and a hybrid also are in the mix, with varied results. The electric-powered Chevrolet Volt (with a gasoline engine "range extender") earns an acceptable rating, while its battery-electric rival, the Nissan Leaf, earns a poor rating.

Nissan expands, shrinks Leaf recall for missing weld points

Chalk this one up to the quirks of the English language. The other day, we had a post on the recall of a small number of 2014 Nissan Leaf EVs that were missing weld spots. The official bulletin from the National Highway Traffic Safety Administration said that "any vehicle missing welds will be replaced, free of charge." We read that as saying that the welds would be replaced, but in fact it's the cars themselves that will be swapped out. NHTSA said that 211 Leafs were potentially involved in this recall, but we heard from Brian Brockman, Nissan's senior manager of corporate communications, that Nissan is actually looking at, "approximately 276" vehicles. More importantly, Brockman clarified that, "If a vehicle is found to be missing the welds, the entire vehicle will be replaced." NHTSA documents on Inside EVs show that Nissan expects just 0.65 percent of those Leafs will need to be replaced. Brockman wouldn't say exactly how many cars Nissan thinks are affected, but 0.65 percent of 276 is just 1.8 vehicles. Brockman did say that, "you'd be correct to say that we expect the number to be very low." Read Nissan's full statement below. Nissan is conducting a Voluntary Recall Campaign on approximately 276 MY2014 LEAF vehicles to inspect the front member assembly welds. Due to an isolated supplier process error that has been corrected, a small number of vehicles within a subset of MY2014 LEAF vehicles manufactured during a two-week period may have front frame member assembly components that were not welded to proper specification. This can affect crash performance. Within the next few weeks, affected LEAF owners will be asked to bring their vehicle to a certified Nissan LEAF dealer for an inspection. If the vehicle is determined to be affected, Nissan will provide owners with a brand new replacement vehicle at no additional cost. A loaner vehicle will be provided during the vehicle exchange process. It is anticipated that only a handful of retailed vehicles are affected by the weld issue and require vehicle replacement. Nissan is committed to a high level of customer service and satisfaction and is working with its dealers to provide an outstanding ownership experience to Nissan LEAF owners.