Does Size Matter? Engine Displacement….How Low Can They Go?

The 1.5L turbo in my wife's Civic is a nice little motor and it's a good match for the CVT. Power application from a stop is nice and smooth and it ramps up quickly if you ask it to. The car certainly isn't slow by any means.
 
I feel we are getting past the "sweet spot" of downsizing and turbocharging for economy gains I rented a Trax a couple of weeks ago with this engine and it was, as expected, an inadequate producer. I'd be more OK with it if it returned excellent MPGs, but it did not. The thing is, when you have to get the turbo spooled up constantly on these little turds just to get moving it negates the economy gains of going with such a small displacement.
Yup. To get the gas mileage you have to reserve the turbo for on-ramps only, and don’t attempt passing.
 
^ hard pass for me. I would think American cars, especially something like a Buick would stick to what they are good at... This seems like an attempt at a Kia / BMW mix.

Are we going to see a future car engine displacement at 1L?

Family member had a ~2015 Prius-C (The compact hatchback) it was a n/a 0.9L 4 cylinder.
Unfortunately, Buick and Oldsmobile and Pontiac all got rounded up into one basket and after losing their own individual identity and distinction were all melted together with the others and quality went 86.
We made big mpg before from the Geo Metro, Yugo, VW Rabbit, Honda CRX HF and Nissan Sentra so I dont understand how hard it would be to get back here again.
 
If you push a smaller engine harder it burns more gasoline at the same power output of a larger engine.

Their is a trade off. I can do a smaller engine with a turbo, giving the operator the extra power when they need it (like passing) and benefit. But if I am pushing high boost on a regular basis, its not worth it.

So in N. America where the going speed on an interstate is 80, a small engine no longer makes sense.

In a Euro City driving only or in the developing world where the roads are not fit for anything more than 40mph, then its a different set of needs and a small engine might be cheaper to run and cheaper up front to make.
 
Maybe not directly caused by it's small displacement, but that engine wasn't very good. Turbo was probably pretty busy and had some issues, and it couldn't keep the coolant in the right places, and also the wet oil pump belt shredded and clogged the oil pump. Ford only recalled them for the oil pump belt.

The wet belts were the only outstanding issues, it didn't have any other known issue; that's how mine died (although it was my fault for not changing the timing belt.) The turbo was fine and it went into boost generally the same as any 4cyl turbo we currently have. There was no known issues with coolant leaking.

For an engine released in 2012, it was pretty good considering the footprint block could fit on a 8.5 x 11 sheet of paper. I would regularly get 40mpg on the highway with it. It wasn't fast by any means but it was faster than a fiesta lol.

I believe the ecosport used the same engine and the bronco sport had an updated version.
 
Sooo ... stock for stock, our 2019 Sentra with a NA 1.8L and CVT was quicker than my 4.6L v8 Grand Marquis 0-60.
Now that I've swapped out the rear axle in the Marquis, I think it can finally do 0-60 in under 13 seconds and beats the Sentra.
 
Ex: Two previously owned Ford Fusions - 2.5 NA with average MPG in the low 30’s and 1.5T with average MPG in the high 20’s.

Basically owned two of the exact same vehicle body wise however the one with the smaller turbo engine did significantly worse in real world MPG.
Depends on drive cycle. The turbo can do better at steady state, but in stop and go the NA will do better. Less power under the curve. I can get great mpg in my Ecoboost if I keep RPM below 2500.
 
I love the little LYX 1.5T paired to a the 6AT in my 2021 Equinox. I'm sure it's tiny turbo spins it's little heart out, but you wouldn't know it. It's smooth, quiet and has great power and economy for what it is. I average 30-34mpg tank to tank and it's AWD. I can point to threads over on GM/Equinox forums I'm on that has owners that claim to have 200-300K miles on all original 2018+ GM LYX 1.5Ts.
 
Unfortunately, Buick and Oldsmobile and Pontiac all got rounded up into one basket and after losing their own individual identity and distinction were all melted together with the others and quality went 86.
We made big mpg before from the Geo Metro, Yugo, VW Rabbit, Honda CRX HF and Nissan Sentra so I dont understand how hard it would be to get back here again.
Very hard: weight.
 
I'm sure there'll be something like the C99 AMG and it will be $300k with a 50cc 1 cyl 2 stroke, the trend is such. People will get used to mixing in the oil with the gas it's a Mercedes
 
Depends on drive cycle. The turbo can do better at steady state, but in stop and go the NA will do better. Less power under the curve. I can get great mpg in my Ecoboost if I keep RPM below 2500.
With my example it didn’t matter if it was steady state or not. The NA did much better than the Ecoboost. Cannot speak to all versions though just the two vehicles I drove.
 
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Feel free to correct here:

I know that tiny engine like this probably aren't going to last as long, but given the smaller size isn't it going to make it much easier to DIY replace the engine?
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If you push a smaller engine harder it burns more gasoline at the same power output of a larger engine.

Their is a trade off. I can do a smaller engine with a turbo, giving the operator the extra power when they need it (like passing) and benefit. But if I am pushing high boost on a regular basis, its not worth it.

So in N. America where the going speed on an interstate is 80, a small engine no longer makes sense.

In a Euro City driving only or in the developing world where the roads are not fit for anything more than 40mph, then its a different set of needs and a small engine might be cheaper to run and cheaper up front to make.
It is all about infrastructure, driving culture, needs, size of the country etc.
In Europe road trip at longest might be Berlin to Croatian beaches or maybe, maybe Spain (not making sense with super cheap air fares).
So, vehicles are made for city driving, tight parking spaces etc. I have there Prado diesel (the GX470 here) and within 5min you get frustrated when in the city.
So, small engines are there in vehicles from 80’s. The turbo which is must add on on those engines last 20-25yrs is there more to deal with increasing weight and emissions. I had 1994 1.4 Opel Corsa and it was fairly zippy vehicle. However, same car today has like 1000lbs more, so turbo comes handy.
Few years back I rented Peugeot “somethibg” (107 or something like that). Regular trunk, made in turkey. Budget version. 1.2 turbo, drove all Croatian coast and Bosnia. Never thought about anything bigger. It just fits into that environment where you must park car between two small trees by the beach. And than when you look gas prices, you appreciate downsizing.
 
Feel free to correct here:

I know that tiny engine like this probably aren't going to last as long, but given the smaller size isn't it going to make it much easier to DIY replace the engine?
Next time you go to Europe take a cab, some small car and ask how many kms they have on vehicle.
 
If you push a smaller engine harder it burns more gasoline at the same power output of a larger engine.

Their is a trade off. I can do a smaller engine with a turbo, giving the operator the extra power when they need it (like passing) and benefit. But if I am pushing high boost on a regular basis, its not worth it.

So in N. America where the going speed on an interstate is 80, a small engine no longer makes sense.

In a Euro City driving only or in the developing world where the roads are not fit for anything more than 40mph, then its a different set of needs and a small engine might be cheaper to run and cheaper up front to make.
All "working" diesel engines with turbos, are using them nearly all the time, and are making power efficiently, so there are no big non-turbo diesels left, as they are too inefficient.
In theory, these small gas DI turbo engines should work the same , but are not so good in reality for some reason? Maybe they are made to game the EPA mileage test, but fail in real life with not so great 87 octane, so they want to ping, and then have to run super rich not to blow up?
I do find it interesting that the "big" 2.5 NA(all with AWD) in the Subaru family matches or beats these GM fwd SUV's in mileage, if not at the drag strip.
 
All "working" diesel engines with turbos, are using them nearly all the time, and are making power efficiently, so there are no big non-turbo diesels left, as they are too inefficient.
In theory, these small gas DI turbo engines should work the same , but are not so good in reality for some reason? Maybe they are made to game the EPA mileage test, but fail in real life with not so great 87 octane, so they want to ping, and then have to run super rich not to blow up?
I do find it interesting that the "big" 2.5 NA(all with AWD) in the Subaru family matches or beats these GM fwd SUV's in mileage, if not at the drag strip.
Good observation.

I know for example at idle or no load MPI is generally more efficient than GDI. But at load GDI is more efficient. This is the primary reason some companies are going to both. Cleaning the intake valves is a side benefit but not the reason.

One would think that a 1.0L in a hybrid would make sense - since you would always run the battery to make up for power and just run the engine more to charge. But they don't seem to do that either. 🤷‍♂️
 
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