Variable compression

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This really was supposed to be ‘just-can’t-be-done-technology’. Just ask Lotus Engineering, Saab and the many other not-so-public engineering projects and teams that tried to crack variable compression design. But, to the credit of Infiniti, well Nissan (but it’s the halo brand that gets the shiny gold star here) the holy grail of IC engine development has been achieved.

There are many things to say about Infiniti’s VC-T engine, and all your techy itches should have been scratched at the start of this issue, but here’s the thing: powertrain engineering never ceases to amaze me. Saying something can’t be done seems to drive on these wonderfully clever people even more. “It can’t be done just means it can’t be done for now,” said Alain Raposo, director of engineering at Renault-Nissan Alliance, in an exclusive interview with ETi at the Paris Motor Show.

And it just so happens that after years of painstaking research and development – sometimes an approach that meant it was one step forward, two back – Infiniti/Nissan has got there first. My oh my, what the fertile soils of this promised land could now reap.

VC-T has a variable compression ratio of 8:1 to 14:1. Yes, you read that right: 8:1 to 14:1! How bloody amazing is that? I mean, seriously, I thought I’d never see the day this technology would jump out from some engineer’s head, off a prototype mounted on a dyno, and be production ready. Because that’s exactly what Infiniti/Nissan has done. This technology, this engine, this brilliant engineering breakthrough is hitting showrooms in 2018!

By cracking the code, the 2.0 VC-T has an arsenal that should get Infiniti’s rivals really worried. Standout claims include power that’s equivalent to much larger six-cylinder designs, even up to 3 liters in capacity; torque outputs that are more commonly seen on performance diesel offerings; benchmark gasoline four-cylinder efficiency; and a smooth, quiet, refined operating mode. There’s much, much more, but that’s just the start.

I have serious respect for Infiniti/Nissan for doing this and not just delivering this breakthrough but persevering with what could have simply been a pipe dream; keeping with it when, perhaps, it would have been easier to step away from the study.

This actually takes me back to what I said earlier. There are many things to say about project VC-T, much of which you’ve probably heard or read, but here’s the thing: aside from getting a big advantage over rival brands, Infiniti/Nissan just might have saved the gasoline engine as we know it. And all this during a time when, we’re told, car makers’ main powertrain efforts should be wholly concentrated on electrification, be that battery, e-motor, fuel cell, or all three. Why waste time, effort and resources cracking variable compression tech when the IC engine is dead?

But the IC engine isn’t dead, of course, and Infiniti/Nissan now has a huge ace card in its engineering portfolio. This is one of those key moments – like when the industry got turbocharging right, applied direct injection, added particulate filters, and even refined cylinder on demand. This really is a historic, watershed moment for the IC engine. And for all its efforts and courage, I really hope Infiniti/Nissan gets the rest right, to use the technology to its fullest and enjoy the fruits of its hard labor.

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About Author

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Dean has been with UKi Media & Events for over a decade, having previously cut his journalistic teeth writing and editing for various automotive and engineering titles. He combines extensive knowledge of all things automotive with a passion for driving, and experience testing countless new vehicles, engines and technologies around the world. As well as his role as editor-in-chief across a range of UKi's media titles, he is also co-chair of the judging panel of the International Engine of the Year Awards.

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