CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

2L /4 turbo engine vs. NA/ Naturally Aspired V6 engine?

Why should I consider a 2L turbo over a V6 engine?

A) Fuel savings?
B)Engine last longer?
C)Less Maintenance?
D) NA engine have a proven track record?
E) … the $cash savings for the Manuf.?

trick question. does car offer both motors? in same trim levels? does both motors have same trans option? like a 6spd vs 8spd? or DCT? or manual?

A) Better fuel economy. THAT is why the manufacturer offers it.

The engine is more expensive to build, so not E). B) Turbo 4’s have been around since about 1974 and turbo engines in cars since about 1961 so durability is all worked out. C) Not less maintenance, about the same.

If you are looking at new vehicles I would not call this a big deciding factor.

Everyone has answered with very good info…

Here is my spin on how to look at it. The 2 liter Turbo is probably equal or greater in power output compared to the V6 at max output/boost ( it will drink fuel with max boost…but that is a temporary situation). However… when not on heavy boost the 4 cyl has the ability to use less fuel…so as long as your foot isnt in it…it can sip fuel…and when you want power…it can do that do. Its much more flexible/versatile really.

The V6 is going to burn more fuel basically at all times because of the number of cylinders to fuel all the time…there’s no way around that.

Also with a Turbo engine you get stronger forged internal con rods and usually pistons…its built of high quality components (or should be) and they indeed are more expensive to build. This is kinda bang for your buck that no one mentions.

Also, with the Turbo, if you ever have a hankering for more power you can reprogram the ecu for …more power… at the expense of fuel…only under heavy boost. We’ve been using fuel for fun since its invention so… I wont judge you if you went there with it. All my Turbo vehicles were “adjusted”…they are fun.

SO it looks as tho I just managed to rewrite what everyone else just said… I’m hopeless…

I’d go with the 2 L

No one has mentioned so far that a possible drawback of the turbo is turbo lag. This varies quite a bit between cars, so you’d want to make sure you’re happy with the one you’re considering.

The choice depends on what you find important, how you plan to use the vehicle, and how long you plan to keep it.

I’ll expand on that later when I’m in front of a computer with a full keyboard.

No personal experience, but one thing for certain, you’ll never have a turbo unit or inter-cooler fail with the 6 banger non-turbo.

2 Likes

You shouldn’t consider the small turbocharged engine. Those models only exist to improve the manufacturer’s CAFE ratings, and to be able to advertise a higher fuel economy figure. There’s no real benefit to you, the owner, versus a larger normally aspirated engine.

This is very similar to the base models of certain cars, which lacked necessary equipment, such as air conditioning or an automatic transmission, and really only existed to allow dealers to advertise a deceptively low “starting price”. It was just a ruse to lure people in with the “draw” of a lower payment that they’d never actually receive, because they’d end up buying a more expensive model with better equipment.

No longer a choice on most all cars/CUVs/SUVs. Turbo 4s are often the only engine available. And it’s no ‘ruse’, it’s the future. Everyone from Alfa to VW.

One major plus for turbo 4’s versus NA 6’s is that there is typically more room to service them in the engine compartment AND you never have to fight with spark plugs wedged against the firewall. I have always bought NA 4’s and just bought my first turbo 4 in my new 2018 Mazda 6. The turbo in the 6 is tuned for lots of low end grunt and very little lag. I don’t even notice it, except for the extra 70 hp when it’s “go” time. I’ll let you know how the fuel economy is and how much I like the power as time goes on.

I haven’t heard of anyone with a turbo failure since my college roommate’s 1984 Dodge Daytona turbo ate one.

Owned 3 turbo 4’s starting in 1985 until now. Never had an intercooler, intake hose or turbo failure. Combined mileage on the first 2 was 195K, years owned 30 total (17 plus 13), the 3rd was bought used and now has 32K on it with no problems. The last 2 had essentially no turbo lag and got over 30 mpg highway in 3700 lb sedans.

friend has an infiniti g37 w/300hp v6. he rented a new model that has a turbo 3.0 that makes 300 hp and he liked it. seems there is a 400 hp model that is also 3.0 but has a different turbo setup and liquid intercooler setup and about 100 other tweaks to make the extra 100hp. maybe the base turbo model is the cheapo model and the 400hp version is the one built with the good bits? who knew. a cheap and not cheap turbo setup

OP, if you live or frequently drive to high altitude locations the turbo will perform better than NA.
Turbo/supercharging was a game changer for piston engine aircraft.

A V-6 is going to have lower RPM torque/hp. This is real useful for towing or hauling. The turbo doesn’t kick in until higher RPM, so not a good choice for towing.

Depending on the engine and the turbo setup the V6 might be easier to work on because of a lot less plumbing.

Mike, that used to be the case, but modern turbo engines are often tuned for lots of low end torque.

2 Likes

Except my turbo 4 Mazda 6 makes 310 lb-ft of torque at only 2,000 rpm. The engine was made for the Mazda CX-9, an SUV built for towing. It’s all about how the turbo is set up and tuned.

1 Like

It would help if we knew which year, make and model we are discussing here. I personally enjoy small Turbo Charged engines, but that’s just me. Turbo lag on late model Turbo engines is really not something to fret over too much, you will feel some level of lag for sure, but the engine ecu and fuel injection do a good job of trying to mitigate this condition in late model Turbo’s. Again you can flash the ecu for higher performance and turbo lag reduction if you were so inclined.

However I do not know what vehicle I we are discussing here…they are not all created equal.

Both engines have advantages. Adding a turbo adds more moving parts, but so does adding two more cylinders.

If I was doing mostly short trips and planned to keep the vehicle until the wheels fall off, I’d lean towards the naturally aspirated V6.

If I was doing long trips on highways and only planned to keep the vehicle for ten years and less than 200,000 miles, I’d lean towards the I4 turbo.

Most modern turbos are twin-scroll designs that tend to produce most of their power at low to mid RPMs even in the lower displacement 4 cylinder applications. Most of the 2 liter turbo 4’s on the market produce peak torque at or around 2000 RPM, and carry that torque up to around 4000 before you see a dip in the torque curve.

5 Likes