"MPGiata" modding thread: aiming for 50 MPG with a 1990 Miata. Update: success, 55 MPG!

[Ecky]

That's about the only thing I miss in my Insight - the lack of lack of roof.

[MetroMPG]

Jumped the shark?


I got the idea from this pic I found:





But that's a much smaller boat.


Also, he should have put that on upside down.


Memories of...

[euromodder]

Originally Posted by MetroMPG

Ha! That's a funny ad - there were no Swift convertbles!

Maybe not in Canuck territory, but we sure did get them over here in Europe

[MetroMPG]

49.98 MPG US = 4.7 L/100 km

SO CLOSE. I HAZ SADS.

Needs more mods!

Also: it's surprisingly hard to get > 40 mpg in short local trips with a cold engine, even with lots of engine-off at appropriate times. This thing really sucks back the fuel when it's cold.

[Stubby79]

trick it in to thinking the engine is warmer, sooner?

[ProDigit]

You can run the coolant fluid low, and use cardboard to keep the engine hotter than factory.
From the factory, all cars are calibrated to work best at 75F.
Anything higher, or lower, is somewhat calibrated by the fuel, but still runs slightly worse than at 75F.
It's always good to do minor mods to achieve that goal when possible.

[19bonestock88]

Why on earth would you run en engine low on coolant?

[Stubby79]

I assume 75f is ambient temp, not engine temp.

And yes, I wouldn't recommend running an engine low on coolant. If you want a similar effect, the higher the antifreeze content, the less heat it can absorb. So in theory, if you ran higher % of traditional antifreeze, the engine should warm up faster. You should still run some water in it, especially if it's going to be below freezing outside, so that it can absorb enough heat, and not freeze. Pure antifreeze freezes not much lower than pure water.

[ProDigit]

Originally Posted by 19bonestock88

Why on earth would you run en engine low on coolant?

To warm up the engine faster. Less coolant, quicker warmup.
You'll be ok with a low coolant level. Low coolant levels are well above the absolute minimum your engine needs to survive.

And yes 75F is ambient. Engines run over 200F.

[MetroMPG]

The air did not really like this setup.



With the boat properly strapped down, I struggled to get ~45 MPG (US) / 5.2 L/100 km on a 150 km round trip at speeds where I'd easily be getting 50+


Partly I think it was because the boat was positioned in line with the passenger side of the car (for outward visibility). Might have worked better dead center.