GM 3-cylinder?

"BaconSandwich is tasty." (baconsandwich)
09/24/2014 at 23:17 • Filed to: None

I'm curious about GM's small 3-cylinder, as described here:

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I really like the idea of the 3-cylinder Ecoboost, and this seems quite interesting as well. It does look like it has a bit lower power output than the Ecoboost, but it's also an aluminum block. By the sounds of it, it is also the same block (albeit differently equipped) that will end up in the next generation Chevy Volt.

It would also seem that these have been out in Europe for a little while now. Has anyone heard much about them? Are they decent?

DISCUSSION (12)

Kanaric > BaconSandwich is tasty.
09/24/2014 at 23:33

The 1.4l turbo could be interesting in the Opel Adam or a similar car.

BaconSandwich is tasty. > Kanaric
09/24/2014 at 23:35

I'm thinking more in a Lotus Super-7 or similar kit car. I wonder if they'll sell it as a crate engine...

Kanaric > BaconSandwich is tasty.
09/24/2014 at 23:39

It would be great in something like that. People want the Ford one for that as well.

BugEyedBimmer - back in the Saddle Dakota Leather > BaconSandwich is tasty.
09/25/2014 at 00:05

I think 3-cylinders are great engines to use in hybrids where the engine basically functions as a generator. However, as an actual engine, it would never work outside of a Kei car. With small displacement turbo engines, you're highly succeptable to the law of diminishing returns. After a certain liter to weight ratio is crossed, you lose fuel economy due to the car always having to be in boost.

mcseanerson > BaconSandwich is tasty.
09/25/2014 at 01:04

In a few years when these cars start hitting the junkyards I want to do an engine swap with a NA Miata with one of these boosted three cylinders.

duurtlang > BugEyedBimmer - back in the Saddle Dakota Leather
09/25/2014 at 04:06

While I don't disagree we're already seeing 1.0L 3-cylinder engines with a turbo in the Ford Focus. In Europe. They've been available for a while now. The problem with these is that while the theoretical fuel economy is great, real world economy isn't that great at all.

BaconSandwich is tasty. > mcseanerson
09/25/2014 at 09:52

How much hp does the NA Miata produce? A nice small aluminum block might be quite a bit lighter.

I like the way you think.

BaconSandwich is tasty. > duurtlang
09/25/2014 at 09:56

From what I've read, you're right - fuel economy numbers aren't as good as they thought they were going to be. I'm going to guess there's a few reasons for that. For one, they might not have quite the same get-up-and-go as a non-turbo engine, so people tend to push them harder off the line. It's also what BugEyedBeetle said - if the engine is always having to work hard, it's going to be using more fuel. A good example of the opposite of that is the Corvette. I've heard it's possible to get something like 30 mpg when cruising on the highway because the engine is hardly having to work at all (a combination of tall gearing, and a huge V8).

That being said, I still want to play with some tiny 3-cylinder engines. They look like fun.

mcseanerson > BaconSandwich is tasty.
09/25/2014 at 10:07

1.8 makes about 130 hp. I'm not interested in a horsepower increase so much as fuel economy gains. NA Miatas weigh less than 1 ton and with a modern turbo 3 should easily break 40 mpg hwy.

BugEyedBimmer - back in the Saddle Dakota Leather > duurtlang
09/25/2014 at 10:36

Just for reference, here's a C/D review of the 1.6 EcoBoost where the car returned 22 mpg. They've gotten better mileage out of most of the ponies and pretty much all of the hot hatches.

http://www.caranddriver.com/reviews/2013-f…

I'm just saying, a car would have to be sub-2500lbs to make any decent efficiency out of a small 3-cylinder.

duurtlang > BugEyedBimmer - back in the Saddle Dakota Leather
09/25/2014 at 13:35

I guess it depends a lot on the driver and the type of traffic. A 3 cylinder vehicle using cruise control with tall gearing and a low drag body at not too high a speed can reach stellar economy, but when that turbo is used all profit is lost.

BugEyedBimmer - back in the Saddle Dakota Leather > duurtlang
09/25/2014 at 13:43

Taller gearing can lug an engine and cause the same issues. There is no way to make these engine work except for drastic weight reduction of the cars they end up in.