2011 Chevrolet Silverado Ltz 3500hd Dura Max 6.6 Allison Transmission on 2040-cars

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2021 BMW M3 and M4 vs all the high-powered sport sedans and coupes

Should you have a found a way to get past that schnoz, you've probably digested some of the basic specs for the all-new 2021 BMW M3 sedan and M4 coupe specs. They're plenty impressive. There's also, basically, two sets of them thanks to the regular and Competition versions that differ in engine output and transmission type.  But how do they compare to other ultra sport sedans and coupes? Well, we were wondering that too, so we fired up the Autoblog Comparison Spreadsheet Generator 5000 (aka me chained to my computer in a dark basement).  Sadly, there are surprisingly few competitors for the 2021 BMW M3. Rival sedans include the Mercedes-AMG C 63 and the Alfa Romeo Giulia Quadrifoglio, along with the Audi RS 5 Sportback sedan/coupe/hatchback thing. There's no more Lexus IS F, the Cadillac CT4 Blackwing has yet to arrive and Jaguar doesn't offer a spicy XE R.  Happily, there are more coupe rivals for the 2021 BMW M4, including the two-door versions of the AMG and Audi as well as the Lexus RC F. I also included the Ford Shelby GT350 and Chevrolet Camaro SS 1LE. On paper, they align incredibly well. On the street and on a track, I can personally attest that these Americans are fully capable of keeping up and/or bettering the fancy-pants luxury brands (and let's not forget there are even more powerful, hardcore versions available). If they don't align in terms of price or prestige, whatever. OK, let's get to the spreadsheet. Let's start with the coupes and note that I didn't bother listing the dimensions for the M4 Competition and C 63 S as they are identical to their "lesser" siblings.  I won't bother burning words explaining what you can see on the chart. Instead, I'll point out a few things that stood out to me. First, BMW M comes awfully close to matching the output of AMG's twin-turbo V8 despite having two fewer cylinders. Similarly, Audi manages to better the 0-60 time of the M4 Competition and tie the C 63 S despite being WAY down on power. It's not like it weighs less. Magic? Second, and speaking of 0-60 times, remember the importance that transmission and drivetrain make with them. It's not just horsepower and torque. An automatic will be quicker and easier to launch than a manual, while all-wheel drive provides more instantaneous and beneficial grip.

2014 Chevrolet Corvette C7 Convertible offers a few more views before reveal

Over the weekend, Chevrolet released its first images of the new 2014 Corvette Stingray Convertible. Now, ahead of the droptop's official introduction tomorrow at the Geneva Motor Show, the automaker has given us a few more shots of the softop C7 showing off the car's rump albeit from a high, strategically positioned angle.
From this angle, it's hard to get a sense for how long and flat the decklid really is, but we can easily see that, like the rest of the C7's design, the new convertible's decklid and tonneau cover are far more detailed than the current car. We also get a better look at the rear haunches sans brake vents, which have apparently been moved to underneath the car in order to accommodate the top's hard cover.
As for the overall styling of the C7 convertible, with the top erected, we get some idea of what a coupe design (as opposed to the Stingray's fastback shape) would look like on this car. The C5 Corvette most recently had a coupe model that did away with the large glass hatchback, and we recently reported on a low-cost "coupe" model potentially being added to the C7's repertoire.

GM opens official investigation into C8 Corvette transmission leaks

In March 2020, a month after Chevrolet began customer deliveries of the 2020 C8 Corvette, a GM dealer technician created a Reddit thread about a leaking gearbox in a Corvette with 32 miles. That car hadn't even been sold yet. Since then, as a search of "C8 Corvette transmission leak" shows, it's been tales of woe for some owners. Something in the Tremec TR-9080 transaxle in the back of the mid-engined Corvette doesn't work as it should, the fault able to cause codes that the transmission needs service, or that the driver needs to shift to park. In some cases, the battery would die because of follow-on issues after the initial transmission code, that code preventing the car from powering down. As Autoevolution reports, GM filed paperwork with the National Highway Traffic Safety Administration in August to look into what's going on. Between forum threads and GM's investigation document, there are several issues mentioned. The most common appears to be the dual-clutch transmission leaking fluid due to gasket failures like the one suffered by one owner at 858 miles, and another for an owner currently enduring a second leaking transmission. The Midengined Corvette Forum reported that Chevy engineers redesigned the TR-9080 pan, fitting Corvettes with the new unit at some point in the 2021 model year. The original pan was stamped steel unit affixed to the engine with two studs and 13 bolts, plus "reinforcement plates." The updated pan is said to be a cast aluminum unit affixed with two studs and 17 bolts, omits the reinforcement plates, and gets a new machined new groove around its edge to seat the gasket seal. The GM paperwork now at the NHTSA mentions a P1789 code, and says one reason for it could be "debris on the park position sensor magnet causing an incorrect position reading to the TCM." This might be caused by another issue mentioned in forums, which is clogged transmission filters. GM gives instructions for returning transmission filters to the company, and a poster on one forum said the Corvette tech at the dealer where he bought his Corvette told him the automaker "requires every used transmission filter to be returned to GM."  Whatever's going on, the problems haven't stopped, and they go beyond the P1789 code. Over the weekend, a 2022 Corvette owner posted on Corvette Forums that he got a check engine light on his car after just 850 miles.