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Help me reduce Fuel Consumption and Improve Top on my Eco Shitbox


#21

Also this video might help with some directions for reasonable eco cars:


#22

I have had servial tests on fuel economy, power etc etc.
I have tried to build competitor for Skoda Kodiak which is farily sizable SUV, with smallest engine being 1.4l Turbo. The downside was that acceleration was abysmal, top speed around 140kmh, and I had to work the engine HARD to keep 120kmh (75mph) “highway” speed going on. which meaned that the fuelconsumption was high.

I have love of 70’s american barges so I have compared 6l V8, carburated vs 3.1l I6 carburated Turbo . just to get them more fuel efficient. Again with big heavy boxy body.
The i6 saved half a litre for 100km, and provided higher top speed (158kmh vs 169kmh tested on BeamNG)
How ever over a lap on Automation Testrack (In BeamNG) the V8 was notably faster due to it’s massive torque advantage.
This was most notable when trying to get from standstill, As the V8 set off with tires chirping, and i6… Well it moved eventually.
As these were driven on 4speed automatic transmission I also noted that holding a speed wityh the V8 was easy, and didnt requitre much changes on throttle position, the I6 needed constant and large throttle adjutments, So much in fact that the gearbox every now and then opted to shift to lower gear.
Also I noted that on 0-100-0(kmh) The V8 had stopped before i6 car started to brake.

What did I learn form these?
Have enough displacement so you can get enough torque, and get the torque on the rev range where you want to have the car on 60 80 and 120kmh speeds on high gear.


#23

Model 2 - Trim 2.car (9.8 KB)

Here is an example, no tech sliders and 4l/100km, 106hp. I used a different more aerodynamic body, but didn’t spend much time fine tuning it.

It would have a max speed of 145 if I hadn’t governed it to 105 to keep the tire cost down.

When you look at the engine power/torque, and efficiency graph it peaks torque and efficiency from 1500-4500 rpm where the engine will be used most often.


#24

Just slapped this thing together


Half irrelevant things.
Tested the car on BeamNG where the top speed ended up being 118kmh (althuogh I had governed it to 150kmh, in automation which suggests top speed 152kmh withuot governing it) How ever there is apparently some form of turbo bug as the boost jumps all over the place and rarely get’s to as high as it shuold be able to be.
Anyhow, that 118kmh was achieved on 5th gear, and the engine was revving at 6k rpm instead of the ideal 3.5k, but I assume this is due the boost bug.
How ever I took a caravan, combined the tow bad node to the cars rear end, and tested the tow capability, and managed to get the caravan on top of the mountain. As the speeds were rather low, on the twisty mountain road, it wwasnt actually even a reas struggle, and the car pulled relatively strongly speeds being around 30-50kmh mostly on 3rd gear.


#25

That’s one of the least aerodynamical bodies, which significantly harms both economy and top speed.

No, that’s only a matter of your gearing setup. RPM to car speed relation is fixed and linear, always and everywhere.


#26

My idea was to use the least aerodynamical, althuogh still relatively light body, Just like OP uses.

And yes I actually shuold have said
"118kmh was achieved on 5th gear, and the engine was revving at 6k rpm instead of the ideal 3.5k, on 6th gear, but due to the boost bug I am losing both power and torque (0.4 bars of boost on Autoamtion, comes out as 0.2 bars in BeamNG) hence the 6th gear becomes unusable oneven ground.