The 40MPG Crown Victoria Challenge

[rmay635703]

Go for the gusto, cars larger than yours got near 40mpg with a 3sp auto and the good old fashioned 5.7 or 4.3 DX block olds Diesel. Put a 5sp with decent gears and your landcruiser will probably get 40mpg. So long as you have good gears and are carefull those motors can pull also. The later goodwrench motors when coupled with a fuel water separator were almost bulletproof. My fathers 79 5.7 diesel pickup is still on the road, he sold it with 120k in 1990 if that means anything.

The 6.2 diesel is very similar to the 5.7 in terms of fuel economy but tows weight around much better, but it would give you a bit of a FE hit, how much I don't know. I do know the "C" series 6.2's tended to be very close to the 5.7 on MPGs though

Cheers
Ryan

[SlideWRX]

Personally I would go with the Final Drive swap, and work on aero. Don't play with the engine/trans till you figure out what you really want to put in there.

2003+ Crown Vics and 2005+ Mustangs have wheels with higher offset, meaning they will tuck into the wheel well a bit more for the wheel cover. Just gotta make sure they clear the brakes and suspension bits.

[mcrews]

go up one size on your tire.
that will lower the final ratio a notch more.

[mystere485]

Originally Posted by mcrews

go up one size on your tire.
that will lower the final ratio a notch more.

We were going to go smaller, perhaps a 195(?) less frontal area i reckon.

Originally Posted by SlideWRX

Personally I would go with the Final Drive swap, and work on aero. Don't play with the engine/trans till you figure out what you really want to put in there.

2003+ Crown Vics and 2005+ Mustangs have wheels with higher offset, meaning they will tuck into the wheel well a bit more for the wheel cover. Just gotta make sure they clear the brakes and suspension bits.

I was reading on crownvic.net and they say the '01 and newer rears will not direct fit the older bodies, and my welding skills are not that great that i would consider making suspension welds.

Originally Posted by rmay635703

Go for the gusto, cars larger than yours got near 40mpg with a 3sp auto and the good old fashioned 5.7 or 4.3 DX block olds Diesel.

I am not entirely against diesel swaps, but I have more experience with benz diesels and would probably swap one of those in if it came down to it. However, for the sake of reliability and to save myself 6 months of retrofitting in my backyard w/out a garage, ..lol... ill just stick with the 4.6l for "now"...

Originally Posted by mekanic

for the air bags look under the same generation Linclon Town Cars. the town car is based on the same chassis. they both have the 8.8 rear axles as well.
Also I have seen and I know ford made 2.47 ratio gear sets for the 8.8 rear axles.

Do you know anything about those systems? The town cars from that era here are well used taxi's, I dont mind replacing air cells but how much of the electronic and mechanical bits are needed to be salvaged from the town car?

I was about to call you bs but i came across a canadian website with this

FORD 8.8 Solid axle & Independent
SOLID AXLE

86-up many Ford fullsized RWD cars w/V8

86-current Mustang V8

87-88 Thunderbird V8

05-up Mustang V8 (31 spline)

83-96 Bronco (mixed apps w/ 9” to 86)

83-96 F150 (mixed apps w/9” to 86)

97-up F150 w/ V6 or 4.6L V8

86-90 Ranger chassis cabs

90-up Ranger w/ 4.0L V6 (some 3.0L also Supercab)

90-01 Explorer/Mountaineer/Navajo SUV

98-02 Expedition/Navigator 4.6L V8



INDEPENDENT SUSPENTION

93-98 Lincoln Continental Mark VIII

99-04 Mustang SVT V8 (31 spline from 03)

89-97 Thunderbird

00-up Lincoln LS (V8)

98-up Explorer/Mountaineer

97-up F150

98-up Expendition/Navigator

02-up Explorer/Mountaineer

03-up Expedition/Navigator (4.6L V8)

Cover Bolts: 10

Ring gear diameter: 8.8”

Pinion shaft diameter/splines: 1.625/28

Axle shaft diameter/splines: 1.29/28 or 1.32/31

Available ratios: 2.26, 2.47, 2.73, 3.08, 3.27, 3.45, 3.55, 3.73, 3.90, 4.10, 4.30, 4.56, 4.88, 5.13, 5.71, 6.14

Im going to call in the morning to see what is available.

[mcrews]

all I can say is .....doesnt ANYBODY read other threads!!!?????

hey run dounut spares for all I care.

you come on saying wowwwwoowowo me 40mpg!!!!
and then you tell me you going to go with a smaller tire???????

you have a BIG car. You just have to have a certain amount of tire on the ground to make the ride feel right.
if your so worried about 'frontal' run bike tires!
the point is, the gain from a taller tire in lower rpm is off set by a slight increase in hieght.
Beside, $20 of coroplast intantly lowers the car and reduces the 'frontal'.

[mystere485]

Originally Posted by mcrews

all I can say is .....doesnt ANYBODY read other threads!!!?????

hey run dounut spares for all I care.

you come on saying wowwwwoowowo me 40mpg!!!!
and then you tell me you going to go with a smaller tire???????

you have a BIG car. You just have to have a certain amount of tire on the ground to make the ride feel right.
if your so worried about 'frontal' run bike tires!
the point is, the gain from a taller tire in lower rpm is off set by a slight increase in hieght.
Beside, $20 of coroplast intantly lowers the car and reduces the 'frontal'.

I proved your theory wrong in the other "thread", by switching from a 245 to a 255 you gained approx. 40,000 inches in one tank of gas. That is less than a mile gain per tank. Im not going to drive the car like i stole it, 195 would be fine and cheaper. I have a set of 195's on volvo rims that i can swap on the vic and do a test run, if they don't ride nice ill look into something else.

Dounut spares are not safe, I wouldn't suggest them to my lawyer.

At the beginning of the thread, I stated that I recently received the car. The car is not active yet. Right now it is a discussion on options for higher mpg. I am looking to get 40mpg out of the car when i am done, I have not gotten 40 mpg nor do i have a base line as of yet.

From the fore mentioned thread:

Quote:
Originally Posted by mcrews
Since 245 is the stock factory tire and 255 the tire I run.....oh and you can read any of my posts and see that I only refer to the advantage of ther one size up tire EVERY time as a key reason for my mpg.
AND I have used a Garmin 360 Nuvi to acuratly calculate my miles on long trips to ACCURATELY document the REAL miles and TRUE MPG

BUT here is the chart from TIRERACK.com on the Kumho's that I run.....

size 245/45ZR18 255/45/18
max psi 50 psi 51psi
tread depth 11/32" 10/32
weight 30lbs. 30lbs
rims 7.5-9" 8-9.5
overall width 9.6" 10.1
tread width 9" 9.3
diameter 26.7" 27”
rev per mile 778 769
-------------------------------------------------------

255/45R18
Section Width: 10.03 in 255 mm
Rim Diameter: 18 in 457.2 mm
Rim Width Range: 8 - 9.5 in
Overall Diameter: 27.03 in 686.56 mm
Sidewall Height: 4.51 in 114.55 mm
Radius: 13.51 in 343.15 mm
Circumference: 84.91 in 2156.7 mm
Revs per Mile: 769.5
Speedometer Difference: 1.312% too slow
Diameter Difference: 1.3%

same basic demensions would you say?

Heres the thing, I may not know everything about tires, but i do know math. You save 10 revolutions per mile, which is:
84.91 inches x 10 revolutions=849.1 inches per mile.

you have what? an 18 gallon tank, at your advertised average of 27mpg you are getting roughly 486 miles from one complete fill-up.

849.1 inches x 486 miles=41,2662.6 inches.
there are 63,360 inches in a mile, which means your getting less than one free mile per fill-up. if you can tell a difference its not from your tires, atleast not from a height stand point.

[roflwaffle]

Originally Posted by comptiger5000

Keep in mind, he's not using this for city driving. On the highway, auto with TCC locked vs manual doesn't make much difference, it's the overall gearing that counts.

As far as lugging it down to 1000 rpm, that's too low to have enough power to do much with in stock form. Plus, it may actually put him below the good part of the BSFC curve. To even think of playing down there, engine mods to increase low end torque are likely needed. In my Jeep, it starts dropping off pretty hard below about 1100 rpm, and my engine is a good bit bigger than his (5.9 liters).

I'd say he should shoot for somewhere in the 1300 - 1400 rpm range, 1500 was the absolute max. After a little research and math, with his stock AODE transmission, stock 215/70R15 or equivalent (26.8" tall) tires, and a 2.73 rear end gear, he will turn 1375 rpm at 60mph. That and aeromods could quite possibly get him very close to 40mpg.

1000 rpm should be OK for BSFC, at least if Ford designs a decent engine. The closest on the wiki is a Toyota V6 that's at ~250g/kWh at 1000rpm and high load. Obviously if the Ford engine can't handle it then it's a moot point.

Anyway, according to the power calculator here an aeromodded crown vic w/ LRR tires would need ~17hp at 65mph. It makes ~225hp at 4800rpm, so at 1500 rpm it would make ~70hp assuming a fairly flat torque curve, so it would be at 1/4 load in that case. There's no engine that's anywhere near a decent level of efficiency at 1/4 load. Even at 1000rpm it would only be at ~1/3rd load, and to see decent efficiency we would need at least ~1/2 load IME.

I'm in complete agreement about there being a negligible difference between a locked up auto and a manual on the highway, but after LRR tires and aeromods I don't see any way to get the load high enough on a 4.6L engine so that it's operating relatively efficiently and can hit 40mpg, and w/o LRR tires/aero mods there's no way the car will hit 40mpg anyway.

[Big Dave]

Tires for MPG is something that gets endlessly discussed on pickup forums. I have seen literally thousands of guys telling me that going to bigger diameter tires reduce MPG every time. Tried it myself and got the same result.

Ask yourself: Why is it that the designers of the first-gen Insight and the Prius (two fangs-out MPG specials) always selected small tires and used gearing to reduce the engine speed at a given road speed?

The answer is angular moment of inertia. Anything that rotates has an analog of mass called angular moment of inertia. AMoI is what makes a flywheel work. Every time you increase road speed you have to not only accelerate the mass of the vehicle, but also accelerate the rotational speed of the tires.

The angular moment of inertia goes up with the square of the radius, so bigger diameter tires bring a very large AMoI that you have to accelerate. This also explains why lighter wheels improve MPG more than you’d think just from the weight advantage.

Gears, although dense, are of much smaller diameter and thus have very small AMoI. Gears, not tires are the way to efficiently control engine speed at a given road speed. This is why I like the T-56 transmission. It is a close-ratio four speed with two overdrives. Fifth gear is a 0.71:1 overdrive and sixth gear is either a 0.63:1 or (more commonly) a stratospheric 0.5:1 overdrive. You can have really small-diameter tires which have very low AMoI and still have a very efficient engine speed with the gearing a T-56 routinely makes available.

If you weren’t just shining us on about wanting 40 MPG, the 4.5 liter gas V-8 and any automatic simply has to go. There isn’t enough aeromodding and weight reduction available to offset that inefficient drivetrain. Probably the best drive train would be a M-B OW 617 and a Getrag 275 five-speed. I suspect you’ll have to go to Germany to source a Getrag 275, but it should mate right up to the OW 617. The OW 617/Getrag 275 combo is probably three hundred pounds lighter than a 4BT3.9/T-56 setup – my second choice. It still gives you a top gear in the 0.7:1 range. The OW 617 will give you about 125 HP max and is legendary for longevity. The OW 617/Getrag 275 is designed for a vehicle roughly the weight of your Crown Vic. (Benzes are heavy.) Downsides: The old-school fuel injection is complex and finicky and the engine is loud by today’s standards. But then, you gotta make sacrifices to get to 40 MPG.

To get to 40 you have to forget gas engines. A diesel is typically 25-50% more efficient than a comparable gas-pig. Look at fueleconomy.gov and contrast a gas VW Jetta vs a TDI diesel Jetta. Generally about 22 MPG for the gas pig and 33 for the TDI. To get to 40 you have to go to war and the diesel is the biggest gun you can use. Even a 2.0 liter EcoBoost (if you could find one) would not give you a 50% bump over your modular V-8.

A lock-up torque converter behind a diesel is going to get you real familiar with a transmission tech. They break down a lot. I had a Chevy pickup with a wimpy old 6.2 diesel and a Turbo-Hydro 700R4. In 300,000 miles I went through seven transmissions. With my Ford (having a ZF six speed) I’m at 290,000 miles on the factory clutch. The manual is also much more conducive to effective hypermiling.

40 MPG in a Crown Vic is do-able, but is ambitious. To get to 40, you are doubling the MPG. You cannot compromise at all.

[winkosmosis]

Not possible! It's a heavy car with a big engine. You aren't going to get to 40mpg.

[Big Dave]

The gas-pig 4.5L V-8 has to be replaced with a diesel.

The slushbox has to be replaced with a stick.

Those two (plus some moderate hypermiling) should get the car over 30.