The 40MPG Crown Victoria Challenge

[kir_kenix]

If the goal is to make the car capable of getting 40mpg on the highway, I'd say its possible with:
+weight reduction (I'm talking seats, glass, etc, etc, etc)
+Gearing (2.73 or similiar)
+Intake & exhaust manifold swap (shoot to make the torque WHERE you need it)
+LRR tires
+serious aero mods
+Alternator/Powersteering/AC deletes....basically all parasitic loads
+Lower her to the ground!
And thats just to get you started.

If the goal is to make this vehicle 40mpg capable city/hwy combined...I'd say you have your work cut out for you. Possible, but way more ambitious than anything I would undertake.

All of this stuff has been mentioned before, but it seems like their are 2 trains of thought here: 40mpg on highway, 40mpg combined. It is my contention that 40mpg on highway is very doable.

Only one way to find out right?

[comptiger5000]

Keep in mind, he's shooting for 40mpg highway and doesn't care much about city. Thus, taller tires, while they can hurt city mileage, shouldn't be a problem on the highway, as they're maintaining a relatively constant speed.

[mystere485]

Originally Posted by comptiger5000

Keep in mind, he's shooting for 40mpg highway and doesn't care much about city. Thus, taller tires, while they can hurt city mileage, shouldn't be a problem on the highway, as they're maintaining a relatively constant speed.

this is true, it will be used for highway driving, 2000+ km trips at a time.

Originally Posted by 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.

there are members getting 24-25 mpg with no mods in their crown vics. Ok, so we use that as a base. First mods:
LRR tires and light weight rims
Replace the engine fan and clutch with an electric assembly
underdrive pulley
build a front air dam and belly pan
block off the bumper intakes and replace the grille with 1992 style model
HAI
tune-up, oil and trans fluid change
get rid of the spare, jack, replace the front bench seats with newer buckets
Replace rear side and quarter glas with plexi
lower car 2 inches

If feasable, swap intake and exhaust manifolds and switch to PI heads.

should these mods not get me to 30 mpg?

[Christ]

Bench versus bucket will be a comfort issue more than anything... The pair of buckets will be close to the same weight as the benches.

Instead of the under drive pulley, which won't help as much as it hurts, remove the power steering pump and belt, a/c pump, and install an ice tray in the cowl where your air comes in. Every stop, check your ice level and replenish as necessary.

You get added weight reduction from the removal of parts and pieces, less resistance to airflow through the radiator bc the ac condenser is gone, less parasitic drag on the engine via belt drives.

In addition to grille blocking, put spats behind the core support so that airflow that does make it through the grille block can't go anywhere but through the radiator.

[comptiger5000]

mystere - The stuff you mentioned (although I agree with Christ, skip the underdrive pulley), especially if combined with taller gears, will get you into the 30s. I would think that if you can gear it tall enough, those mods alone could see 35 or so.

If it's a serpentine belt, ditching the PS and A/C might require bypass pulleys to make everything work properly, and still spin the water pump the correct direction. I'm sure a pulley is available for the A/C, but the PS may or may not be. Plus, in a big car like that, I'd want to do a little testing before just dumping the power steering, especially if it's a recirculating ball steering box, as they can be damaged by lack of fluid flow unless it's meant to be used as a manual steering box.

[Christ]

The crown vic that my father had (80 something) got right at 20 mpg, probably 80/20 highway. It never had fluid in the ps pump, and even so, wasn't altogether difficult to steer.

Usually when you remove a/c and ps from a serp setup, you can use the idler pulley as a reverser to keep the correct belt orientation for the water pump.

Some other things to consider are a ground wire set, cleaning the existing grounds, a dc/dc converter to up the system voltage to 13.5 (electronics will have less amp draw), alternator cutout switch, electric water pump, probably more.

With some work, we'll get you to 40 highway!

[Frank Lee]

This thing will never see 40 without a drivetrain swap.

[dcb]

don't forget stripping off the body and seats down to the frame and installing a lawn chair

[Frank Lee]

Exactly!

[some_other_dave]

If you're willing to drive 45 MPH on your highway trips, that will help a lot...

-soD