Highest Efficiency NA

[Drummerdude48]

We have some awesome efficiency turbo engines floating around but just out of interest I'm wondering what the highest efficiency % of a Naturally Asperated engine is? Lets see who can come up with the highest figure :p

[Reaper392]

I had an old I4 that I made for economy back when I only had the demo. A few tweaks later and it comes out at 40.69% (0.311lb/hph), although its now its only use would be as an oversized, underpowered generator because some of the modifications that gave a slight economy increase made it drastically worse in other areas. As a 1.9L 120bhp engine (with a rediculous build time) it was at 40.20%


*edit*
managed 40.76% with broadly the same settings by switching to an I6 and 40.85% with a flatplane V8. wont bother with screenies though

[Junny]

40% @ 1800rpm is pretty much the same as a modern deisel engine. With a decent cvt or something behind it would power a eco hatch nicely. Good job!

[theagentxero]

This was my fuel economy attempt, I'm not much for being practical... with my 5.3L Quad-Cam v8

[lztd15]

This is my cleanest engine

[theagentxero]

This is my cleanest engine

That's amazingly efficient, but this thread is on Naturally Aspirated or N/A engines, and that engine is a turbo.

[lztd15]

This is my cleanest engine

That's amazingly efficient, but this thread is on Naturally Aspirated or N/A engines, and that engine is a turbo.

[07CobaltGirl]

Here is my attempt. 10.9L DOHC DI with 40% eco and (almost) runs on pump gas.



I was able to get it at 38% without touching any quality sliders, but to break 40% it had to be touched.

[Razyx]

1.4l NA labeled as nut or chestnut hehe.

[dchbrown]

My attempt using the quality sliders and the year (attached)

[ED209]

The best I could do is 45.74% economy

[nialloftara]

Just finished tuning this little baby, only have them demo still but here you go. 46.14% @ .274

[Razyx]

I've downgraded the cc.

[nialloftara]

lowered my cc, put the year up to 2020. tuned to 47%

[gsb216200]

My inline 6 Turbo engine I decreased it to a 1.6L to fit in the current car bodies and it gets 63mpg in the hatch of course when you decrease the size the fuel efficiency goes down to like 25%

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