Friendly Wager: 60 mpg 95 Mercury Tracer

[aerohead]

* I dug through my waking nightmare and did some internet searching.
* Length- 170.9-inches
* Width- 66.7-inches
* Height- 52.7-inches
* Cd 0.35 for the notchback
* Frontal Projected Area, ( Af ) not published, so using the Ford Tempo, who shares very similar W & H, @ 84.91% gross area, = approx. 20.726 sq-ft
* CdA = approx. 7.25428 sq-ft
* Curb Weight = 2,463- pounds
* EPA Test Weight = 2,763- pounds
* Length / square-root of Af = approx. 3.12826
* Engine = 65% energy loss, @ constant-velocity cruise, warmed, straight, level, dry, calm, no acceleration, no deceleration.
* Engine accessories = 2.2% energy loss
* A4 Overdrive Transaxle = 7.81% energy loss
* Regular Unleaded, Reformulated, E10 Ethanol = 111,836 Btu / gallon
* 3412- Btu / kWh
* 2,546 Btu / bhp-hour
* @ 60- mpg @ 55-mph = 0.91666-gallons/ hour
* 5.6264 -pounds/ hour
* @ 6.138-pounds / gallon, mass
* 13.2-gallons capacity
* 432.6597- kWh 'pack'
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* The most interesting data from my archive has to do with the 1994, Euro-spec, Ford Mystique ( Mondeo / Contour )
* L- 176.4"
* W- 68.8"
* H- 54.0"
* Cd 0.31
* Af 22.06 sq-ft
* CdA 6.838 sq-ft
* L / sq-root of Af = 3.12978
* Curb Weight 2850- lb
* 1.989- liter
* Manual 5-speed
* 56-mpg @ 56-mph
* 45-mpg @ 75-mph
* 1-gallon / hour @ 56-mph
* 6.138- pounds fuel / hour
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* Tracers 'bar-graph' is nearly identical to the Mystique, suggesting that if morphed into the Mystique shape, she'd reach Cd 0.31 with no added length.
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* To get from 56-mpg, to 60-mpg, would require on the order of Cd 0.26, if you did everything with aero mods. And that presumes an equivalent BSFC as that of the Mystique.
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* A 15- car average for Cd 0.26 cars yielded and average L/ H = 3.4226.
* Based on the Tracers Height, she would need an additional 9.463-inches elongation to have a chance at Cd 0.26, or 180.363"
* Tracer's L/W ratio for Cd 0.26 would be easily satisfied at a length of 180.363-inches.
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A hard look at what an extended-length, Mondeo/Contour/Mystique would look like, would tell a lot about Tracer's body-morphing requirements, to get you in the hunt.

[M_a_t_t]

Originally Posted by aerohead

* Frontal Projected Area, ( Af ) not published...

* EPA Test Weight = 2,763- pounds

* Engine accessories = 2.2% energy loss

I don't know the source, but the ecomodder wiki lists the 3rd generation (97-02) ford escort as 19.8 sq ft. The unibody is shared with the 2nd generation car (91-96) so I assume it must be close to an accurate number for this tracer.

https://ecomodder.com/wiki/Vehicle_C...t_of_Drag_List

I have had the car weighed at the scrap yard and an "as driven" number for the car is currently 2,509 lbs. If I take the loose stuff out (spare wheel, tools, etc) I can quickly drop it close to 2400.

I have deleted everything but the alternator from the accessories and the water pump is timing belt driven.

Thanks for the comparison.

I was also thinking about lowering the car some, which might help with the L/H ratio. But to not lengthen it at all I would have to lower it by ~2.6 inches. I think that is lower than the bolt on kits allow for the car.

Originally Posted by cRiPpLe_rOoStEr

Interesting idea. Maybe you could take a look on some bicycle racks which feature their own lights and carry another registration plate of the vehicle. Let's suppose you could make something like a removable mini bumper and attach it to the boat tail.

I was originally thinking something similar to Vman's tail. I haven't re-read it, but I think because his prius is a hatchback he had to have a pretty large gap, making it not very effective. I had a few napkin drawing ideas that I could try since mine is a trunk though. I also was thinking depending on the trailer maybe I could mount the boat tail to the back of it when it isn't on the car. Possibly helping the towed mileage still.

[freebeard]

Get a second trunk lid you can drill holes in and put big gas struts on it. Then you could have a smoothly integrated Bonneville spoiler and a collapsible boxed cavity to expose the [suggested] trailer hitch.

[cRiPpLe_rOoStEr]

Originally Posted by M_a_t_t

I think because his prius is a hatchback he had to have a pretty large gap, making it not very effective. I had a few napkin drawing ideas that I could try since mine is a trunk though

Easier than extending the stock hatchback, or replacing it with a custom-made one which would act as a boat-tail.