Putting a four cylinder engine in a full-size truck is kind of like taking the alcohol out of beer. It can be done.
But why do it?
There’s no obvious advantage to doing it.
The little engine struggles to move the big truck . . . on its own steam. It needs heavy turbocharging to make up for its lack of displacement. Which is like skipping breakfast and then eating a really big lunch and hoping you’ll lose weight.
Adding the turbo also adds parts for the sake of losing cylinders – which adds to the cost of the truck. You’ll pay more to buy it – and you’ll probably pay more to service it, too.
It also adds pressure – as the little engine is almost constantly under boost to make up for the power it doesn’t have (without the turbo boost) because of its small size. And even with the boost, it hasn’t got the gumption of a V8 and so isn’t as suited for work, such as towing and hauling things.
These are the things a truck is ostensibly designed to do. A truck that isn’t capable of such things (or which is less capable) is a lot like beer without booze.
Yet Chevy is going to put a little four – just 2.7 liters – in the 2019 Silverado. It replaces the currently standard 4.3 liter V6 and is destined (unless the political landscape does a parking brake 180) to be the eventual replacement for the current Silverado’s politically incorrect 5.3 and 6.2 liter V8s.
And Chevy isn’t the only one.
A whole beauty aisle of lipstick has been devoted to dressing up this particular pig. Chevy touts a “14 percent ” uptick in fuel economy – which translates to 20 city, 23 highway.
It sounds like something momentous or at least significant – until you have a look at the MPG specs of the current Silverado’s 5.3 liter V8. It rates 17 city, 23 highway.
You just saved three miles-per-gallon!
In city driving.
On the highway, it’s a draw vs. the V8. And also (both city and highway) vs. the 4.3 V6, which rates 17 city, 22 highway – and does it without the cost-adding of turbocharging. The outgoing 4.3 V6 may not be as powerful – the turbo four makes 310 hp vs. 285 for the V6 – but the V6 had simplicity on its side, which is synonymous (usually) with lower cost, especially over a vehicle’s lifetime. That matters to a truck buyer, who is often the sort to keep his truck for 20-plus years. Which engine – the V6 or a turbo’d four – would you bet on to ride out those 20 years largely incident free?
The touted mileage is theoretical best case, too.
Out in the real world, the turbo four-powered Chevy will likely return less-than-best-case mileage because the best-case mileage touted depends heavily on the tiny engine not being turbo-boosted.
In theory, this is the Yellow Brick Road to higher gas mileage. Everyone lock arms now – let’s skip to the music!
Follow, follow follow the Yellow Brick Road!
But when the remaining cylinders are force fed – stuffed with air at 22 PSI by the turbo, to increase the effective size of the engine – in order to get the otherwise inadequate little engine to make enough power to keep the truck moving decently – the theoretical mileage will gains will probably disappear.
Big V8 or small, heavily turbocharged four – it takes “x” horsepower to get a vehicle going. And that takes burning “Y” amount of fuel. In the end, it doesn’t matter whether the engine is a big V8 or a tiny turbo’d four.
Except on the government’s mileage tests. And here’s the scoop you’ve been waiting for – or at least, the explanation for this inanity.
Not pulling – or carrying.
Definitely not hauling any ass.
If you’re just sitting in your four-cylinder truck – engine off or just idling – then sure, you’ll burn a little less gas than you would idling the same truck with a big V8 under its hood.
It’s not much less . . but that 3 or so MPG improvement Chevy’s touting is a very big deal to Chevy when it comes time to calculate Corporate Average Fuel Economy (CAFE) numbers, which is the main reason for this engine being put where it doesn’t belong.
And now that fuel economy is being conflated with exhaust emissions – “climate changing carbon dioxiiiiiiiiiiiiiiide” – Chevy and Ford (and everyone else skipping down the Yellow Brick Road) can claim a reduction in “greenhouse gas emissions,” too.
It’s all pretty silly – and very disingenuous.
It’s also the canary in the coal mine.
Chevy – and everyone else making big trucks – can’t go much smaller under the hood. Turbos can only compensate for so much lost displacement.
Yet buyers still want large trucks – with big capability.
Meanwhile, the mileage mandates go up or threaten to – and the political pressure to downsize the “carbon footprint” of vehicles increases.
At some point, not too far distant, something’s going to have to give.
Either it will be acceptance of downsized, down-powered trucks that can’t do the things people need and want their trucks to be capable of doing… or enough people will decide they’ve finally had enough nudging and throw open their windows and scream that they’re not going to take it anymore.
It’s been a long time coming.
. . .
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