Another HyperMile attempt with my 450

[ASmartMan]

Howdy All

Well the first blip went out @ 126 YEP even lower than the last attempt (maybe I was scapegoating the acetone) regardless I always use the same pump and try to do the same # of post fill clicks.

If the next blip goes out as quickly as I expect it too then it’s rethink time.

1: did the acetone really drive down my MPG, I am currently neutral about this (Flip Flop).

2: something I spoke last year about (reduced gas mileage in the winter) the effect lights and the heater has (as a load) on the motor, all that electrical power isn’t free.

After the next blip goes out (because I assume it will be quick), I will stop this test (it takes a fair amount of effort to focus on hypermileing). My trip computer has a “Calculated Load” option on it and a quick test I did with the load of the lights and heater on the motor @ idle, I was able to see a numerical difference.

That will be a different post, I first have to get the HP graph off a UK site for the RPM vs HP and try to come up with a formula to correlate my trip computer to the Dyno graph (if possible).

In the mornings now, my lights and heater are on all the way to work, because it’s back roads (no traffic) Hi Beams are on as well. The low beams are 55 watts each and I believe the Hi Beams are 65 watts, so that’s 240 watts there (not counting the heater or indicator lamps), this load is the same regardless if your hypermileing or driving normal (same wattage load).

This is JUST an analogy to draw the mental picture, but 1st some numbers.
1 Horse Power = 746 watts
Average alternator is about 70 % efficient (if memory serves me correctly)
So @ 70% efficiently 1 Horse Power will generate 522 watts
With the lights, indicators and heater on (I’ll get the real #s this weekend) I would guess I’m running in the 400 watt range.

So I need ¾ horse (at idle or at 70 MPH) from the motor to support the electrical needs of the car, if @ 70 the car is using 25 HP to maintain the speed, then the lights are only taking away 3% of my motors out put effecting my mileage the same.

Now to maintain 35 Mph in 6th gear on the back roads I may only need 10 HP but the wattage load remains the same having a 7.5% effect on the motor load and MPG.

Don’t take this post to heart, I'm guessing (good guess, yet guessing just the same), I have all the electrical equipment at home to get accurate #s, and I can do a dyno run using my trip computer (not a real dyno, calculated, and as long as the fake dyno and a real dyno from the UK trend/graph the same then real info can be gotten).


More to follow this weekend

ASM

[ASmartMan]

Hey All

Well as can be expected I got horrid MPG (High 40's), but not the reason for the post.

I got SSOO busy last weekend (even though I brought home all needed equipment) I never got a chance to test my theory about the load the alternator plays.

I plan on playing with my trip computer (it measures "Load") and it's ability to act as a dyno.

ALL I need to figure out is Cf/Drag (Yea right, like that is a number I know off the top of my head) and the gear ratio for the gear I plan on doing the test in.

Easy, YET not as easy as planed

Will update

ASM

[a2jack]

ASM. I remember someone (about 2mos ago) did the CF/drag for the Smart and posted it here on the list. I think it was on a 450.

Might try search, or ask a Mod to help you find it.

Looking forward to seeing your MPG results.

A2Jack

[chieftmc]

Originally Posted by a2jack

ASM. ...

Might try search, ... help you find it.

Good one a2jack

[Mike T]

The 450 has a 0.37 drag coefficient.

The frontal area of the 450 is 1.95 square metres, so the SCd is 0.7215.


The 451 has a 0.35 drag coefficient, according to Le Moniteur Automobile.

The frontal area of the 451 is 2.057 square metres, so its SCd is 0.7196.

[ASmartMan]

Mike T

Thanks, I knew someone out there knew the answer

ASM