Well, I checked my fuel economy on this last highway trip I took. I drove totally normal, none of that hypermilling stuff, but I also didn't out right floor it at any point either.

I ended up getting 27.1 miles to the gallon on that half-tank of gas. This was drivin an average of 70 miles an hour. Not bad!

The modifications I have are listed in my sig. The ONLY things I don't actually have installed are the large capacity transmission pan, and the magnaflow catalytic converter / header pipes (which will probably make a difference when installed). I HAVE them... hahah... I just haven't installed them yet (I don't have the cats listed in my sig below, but everything else in my sig is installed).

This is significantly better than what I had before. I just swapped out my front tires (OEM Michelin) with a set of Goodyear Comfort Treads. I still have the OEM ones in the back, but they still have like another 15k miles on them so I just couldn't justify replacing them yet. Maybe next summer.

Overall though, I'm pretty happy. I'm going to go with that low resistance water pump, install the new magnaflow cats, and that wind deflector thing that goes under the trunk / rear bumper. My goal is to hit 28 miles to the gallon.

Right now, it's the most fuel efficient highway vehicle I have right now. It gets better fuel economy than my wife's 2004 VW Beetle (which has a 2.0 L4) and my 2006 Pontiac Solstice with the 2.4 VVT L4. Both of those cars average about 26 on the highway.


Just thought I'd mention this in case anyone is curious.

I DO still have my 2.73:1 gears. I plan to get an LSD unit for it as well (sounds crazy, but I need it when I want to get a move on in the rain from a stop light).

Wow, that's great - I can't seem to get more than about 22-23 highway out of my 02 HPP. However, if I'm not mistaken, I think that my car has a steeper rear axle ratio?

Even at my mileage there are always people surprised that these cars even get into the 20's on mileage!

Thanks! Yeah, that's definitely because of your gearing. I think the HPP came with something like a 3.55:1 gear ratio, or at LEAST a 3.23:1.

I figure I should be able to pick up a couple more tenths in the MPG with the magnaflow cats. I'm really hoping to hit 28, that's my goal. I need a tune-up too. I have 38k miles, but haven't changed any of the fluids yet (except tranny and engine).

Yeah, people are always amazed when I tell them what kind of fuel economy I get...

You are not going to make any mileage increases with different exhaust or cats on a modern EFI vehicle with full OBD-II emissions controls.

Lower the vehicle, lower the RAR#, run XL or ULRR tires, SLOW DOWN, keep air from getting under the vehicle.

I respectfully, but completely, disagree. When you improve the flow of the engine, you are in effect improving it's efficiency and performance (more horsepower). When you do that, the engine takes less effort to perform the same exact actions it once did before the modifications. Therefore, getting up to speed, accelerating, and even sustainig speed (since the motor now performs better at that same speed and has an easier time counter-acting the wind resistance, even though the co-efficient of drag has not changed).

It's all about efficiency. If the engine can use LESS fuel to perform the same actions, you have improved it's fuel economy.

This 2002 Crown Victoria was absolutley NEVER capable of producing these kinds of fuel economy numbers when I first got it with 12k miles on it.

Wind resistance / drag co-efficient, and friction of course also play a big part... but there's more to it than that. There is nothing that has inherently changed about an OBD-1 system and an OBD-2 system other than the fact that the bus is more advanced. Most modern OBD-1 systems have pretty much the same sensors and capability as most average OBD-2 systems. I mean, I don't know about Fords... but that certainly goes for GM and Volkswagen / Porsche / Bosch stuff.

engine is an air pump. Let the air out better (free flow exhaust) and you'll make it's job easier. This should give you slightly better mileage.

Also try full synthetic: tranny, gear and crankcase oils. that will help too.

You've had those cats a while! Apply a thin coat of oil to them so that they don't rust before you put them on! It's realy not hard to do that yourself. (magnaflow cats)

I recently went from single to duals along with the Magnaflow cats. I saw no improvement in MPG as of yet. Been almost two months now.

I did magnaflow cats too and couldn't tell you if there was any improvement as I did PI cams and PI intake and the electric water pump at the same time. What I can tell you is that the downpipes are easy to install. Took less than an hour for me and someone inexperienced should take less than 2 hours. Its only 8 nuts and 4 O2 sensors that have to be removed.

I had been getting about 25 mpg since I got my 2004 several years ago. I drive a long way to work on the freeway and usually go between 70 and 80, with the flow of traffic. Lately, when gas prices jumped up I slowed down to 60 to 65. I also try to anticipate the need to slow down, and allow time to coast down rather than brake. My mileage has jumped up to the mid 27 to mid 28 mpg. Or, I used to fill up at 420 miles on the odometer now it's more like 460 (when the fuel light comes on).

Increasing mileage by 10% is not insignificant. That is like giving myself a 45 cent per gallon discount on gas. I also think good lubes in the engine, trans, and especially the differential help alot too.

You ain't gonna get good MPG going at 70-80mph !!

Get them engine revs down, 50-60mph is the optimum speed for top MPG.

I know you're gonna be as popular as tweed underpants going at that speed on the Freeway, but Gas is real expencsive these days !

Rancho Murrieta? Everybody is rich out there. Yes? NO? I get 12, if that. This car is fun. And then sommmmmmme!

yes these cars can be fun. but they got the 2.73 gears which is the reason for thier mpg. u got 3.55's i got 3.27. we will never get that kind of mpg, but do we want to?? lol... wait till we pull up next to them at i light.. they will want the mods and gears then.. promise.. lmfao!!! with the way i drive (big time lead foot) im getting around 16, but im mostly stop and go. i drive on the highway, but for like 9 miles to get to work and driving home at 4 or 5 am?? lets say the traffic does not do 70. lol.. if u do 70 at that time here in dallas?? yea u will get rear ended..lol.... last trip i took to hot springs, i got like 22mpg doing 75mph. so i was happy. just around town mpg is not that great as i got this heavy foot :P:P

but if i actually drove normal?? i could get 18-20 around town no prob.... but if i want to save on gas?? i will jump in my 1997 Taurus that has 180k on it and still gets 320+ miles per tank and costs like $40 to fill it up :P:P:P

Same here. 7-10 miles and i'm there. Back home late at night 1am or so and traffic is light and I'm in the no.1 lane at 80.

Love that late night driving. Best time to be on the road.

My car barely warms up going back at night. By the time I reach my driveway at 1 am, it's begging for me to pull back out and give it another run. Hate to turn it off with all that water in the exhaust pipes. Ha!

Hey man, sorry to burst your bubble... heheh... but I've got all the mods you have and more, and I still have my 2.73:1 gears. It's been proven time and time again that the lower gear ratio doesn't really have much, if any affect on the quarter mile time on our cars.

You might beat me off the line, but I guarantee to you that by the time you hit the other side of the intersection, you'll see a silver streak flying past you. Well... as much of a streak as a car just breaking into the high 14s would make as it passes a car that's running mid 15s.

1992 Crown Vic used police car totally stock
150k on the engine
3838 miles driven in 2005 vacation
140 gallons used
Driven at steady 60 to 65 mph
27.4 MPG average