I'm new... don't flame me! Crown Victoria

Discussion in 'Fuel Economy' started by 73VWTodd, Mar 30, 2013.

  1. 73VWTodd

    73VWTodd New Member

    Hey guys,

    I'm new to this forum (obviously), and I'm always pretty OCD about my fuel economy. I don't /exactly/ have the most fuel economic cars... but I try to do the best I can.

    My wife has a new Jeep Patriot with a 5-Speed, and we typically get mid-30s in that with her driving. On highway trips, I've been able to get close to 40 doing about 70mph.

    My daily driver is pretty horrendous, but I've had it for a while and I do mostly in-town driving. It doesn't seem to make sense for me at this moment to replace it with something when it still works perfectly fine. But I'll just say it, it's a 2002 Ford Explorer that gets 23mpg on the highway, hahaha... it's horrible. I know. I plan to keep it for a couple of more years, and then I'm either looking at a diesel Jetta wagon, or perhaps a Ford Fiesta or Focus.

    My real reason for being here, however... is a goal of mine to try to achieve 35mpg highway fuel economy with my 2002 Ford Crown Victoria LX. (dead serious here).

    I inherited this car from my grandfather back in 2004. The car only has maybe 20 thousand miles on it, and it's not only immaculate, but it's totally loaded with every option it was available with as a non-sport model. So before I go any further, I've tried a few things to "improve the efficiency" of the engine, and I've so far had some pretty decent results. My goal is to prove to the other guys on the CV forums that you can have decent power while also improving fuel economy... more specifically that, by improving the efficiency of the engine (with driving style of course), you can both increase power AND improve fuel economy.

    I say this because MANY people want to be able to go fast... so the very first thing they do is put really short gears on their car... like 3.27:1 is considered menial to these guys. They usually go with 3.55 at minimum, and all the way up to 4.10:1.

    Here's where I'm at... I've been able to achieve 28.8 miles to the gallon (US gallon) in my Crown Victoria on a highway trip from Fort Lauderdale to Orlando. The ambient temperature was about ~75, and I had the car in cruise control at ~70mph, with as minimal braking or accel/deccel as possible.

    So, I can get this kind of fuel economy while at the same time STILL being able to achieve a high 14 second quarter mile time using my 2.73:1 rear-gears.

    There is a guy on the Ford Explorer forum that has been able to achieve 32mpg highway in his Ford Explorer Sport (similar to mine), so I KNOW that if an SUV like that can achieve 32, my goal of 35 SHOULD be attainable when the stars and the moon align. I realize this probably seems stupid or trivial to many who are actively doing well over 40mpg, but I think there's a larger lesson to learn from this for the people who improve their cars with the sole purpose of improving performance. My Crown Victoria is pretty damn fast. It'll tear down a factory police P71 with little effort, while still totally beating it's factory fuel economy. Last I checked, the EPA estimates for my Crown Victoria were about 25, so I'm not doing all that much better than stock, but I think I can do more. I have an ACE in the hole (a fuel stepping device that I will probably install), but I'd like to use that as a last resort so as to improve everything else first.

    So, as a new user here, I was hoping to ask if there are any others who have some non-fuel efficient cars that they are trying to improve (for whatever the reason), what are some other areas I can look at, and whether or not you seem to think it's achievable.

    Oh, if anyone cares, here's pictures of the car: http://www.pontiacperformance.net/car02CrownVic.html


  2. ALS

    ALS Super Moderator Staff Member

    Hi Todd,

    Well there are some basic items you can address in the car. The first is you need to learn to slow down in that beast. Higher the rpms the more gas you are using. Also the aerodynamic are terrible and the faster you go over 55 mph the worse the fuel mileage will get. Pump the tires up a few pounds over door sticker and at or less than maximum sidewall. Next make sure you are using the thinnest synthetic motor oil recommended in your owners manual. Also fill the automatic and rear end with a high quality synthetic fluid if they are not already. Make sure the car is kept in alinement also. Many people never realize how much gas is lost to a mis- aligned vehicle.

    Just for a reference on speed vs fuel mileage I'll show you with my Volvo 960 2.9L
    which I mpg tested on route 41 between Naples and Miami. The EPA rates the car at 24 mpg highway.

    50 mph 35.4 mpg
    55 mph 33.9 mpg
    60 mph 31.15 mpg
    65 mph 28.5 mpg

    This speed vs fuel mileage comparison applies to all vehicles , at least you have 2.73's vs my Volvo's 3.73's. :(

    If I run the speed limit (70 mph) from Pittsburgh to Naples I get a whopping 25.5 mpg.

    Last edited: Mar 30, 2013
  3. herm

    herm Well-Known Member

    Very nice looking car.. you could try slowing down to 65mph, pump up the tires way past the limits and then you always have FAS or the milder methods.

    The secret is to load down the engine at cruise speed, thats usually the most efficient setting. One of those electric overdrives in the driveshaft?
  4. phoebeisis

    phoebeisis Well-Known Member


    Yes-very nice car-the leather looks perfect!!
    I have become a GM booster lately-so I have to slam your Ford-Found On Road Dead-Fixed On Road Daily-so considered it slammed.

    In any case ALS and Herm covered it.
    Speed kills-
    28 mpg at 70 mph-means that car is in EXCELLENT SHAPE-
    You might get a couple 1/10th with the thinnest syn lubes Trans fluid diff lube that still meet specs-and 40 psi vs 35 psi will get you maybe another 1/10th
    BUT like they said- NOTHING will pay off like a 5 mph drop in speed.
    Guess 65 mph would get you 2 mpg-62mph probably 3 mpg

    I also drive a NOT FE vehicle-98 Suburban-folks here are OK with it-this is a run what you brung forum-lotta DIVERSITY- near commies and near fascists all get along-

    My Suburban gets 21.2 mpg on long 3000 mile roundtrips New Orleans to Flagstaff AZ-
    but I average maybe 62 mph-CC set to 67 mph but plenty of road work zones-45mph- fair number of cities-so actual driving speed more like 62mph-
    Glide up hills-cut CC early when coming to lower speed zones
    You Crown Vic-should get about 30 mpg at 63-65 mph with 40 psi tires-pretty good for an older gen RWD V-8 comfortable older car.
    DWL driving with load-means you let speed bleed off going uphill-and get it back downhill.
    It helps on overpasses mountains etc
  5. herm

    herm Well-Known Member

    Will it hurt that transmission to glide in neutral?
  6. ALS

    ALS Super Moderator Staff Member

    It is Conservatives, Libertarians, Liberals, Progressives, Socialists, Fascists and then Communists. The Fascists sit between the Socialists and the Commies. :p

    We run the gambit up to the socialists, I haven't knowingly run across a Fascist or Communist on the board yet, but there is always a first time.
    Last edited: Mar 30, 2013
  7. herm

    herm Well-Known Member

    " Fascist or Communist ".. that one is a subtle difference, in one you are allowed to own the means of production but you better make what the state wants.
  8. 08EscapeHybrid

    08EscapeHybrid Moderator

    The full size Fords have had excellent economy since the 80's when they put electronic fuel injection and 4 speed overdrive transmissions in them. I used to get upper 20's in my great aunt's 88 Lincoln Town car, and my grandfather used to always buy big Mercuries. He loved the Grand Marquis. I can easily get over 30 MPG in Grandpa's Grand Marquis. The mileage really goes down over 65 MPH. If you're looking for impressive numbers, set the cruise at 55-60 MPH When I drive Grandpa's car I try to keep the RPM's under 2.000.

    I would not mess with trying to do neutral glides. Too easy to screw up an automatic. Plus, if you do neutral glides, the engine won't DFCO going downhill.
  9. X3 they let anyone in here. I'm here with a 3500 crew cab long bed truck and 2500 van.


    I've hit 30's mpgs in my truck on a few trips. You should be able to hit your goal.
  10. Unleaded

    Unleaded Well-Known Member

    Hi Todd,

    Welcome to Cleanmpg! Good to know of another member who owns a ford panther. I own a 1996 Lincoln Town Car which is Lincolns version of the Crown Victoria. Too bad your car does not have the digital dash like mine does.

    My mpg record so far has been 39.8mpg from Springerville, AZ to Mesa, AZ. However that was one way and that route is mostly a decent consisting plenty use of deceloration fuel cut-off. If I were to go the opposite direction, I probably would only get 28mpg.

    Averaging 35mpg may be possible but would require LOTS of work. You would have to throw the book at it. Gliding in Neutral with the engine off is a no no with our transmissions.

    While driving on I-80 through Nebraska, I have been able to get the average mpg up to 33.1 before the traffic ruined it :mad: (Traffic jam which brought the mpg down to 26). If not for the traffic I have no doubt that I would have reached 34mpg.

    During that drive, I kept a base speed of 60. Kept the pedal in the same position. Once approaching an incline, I kept the pedal in the same position and let the speed drop to a minimum of 50. Once over the incline (keeping the same pedal position) let the speed increase up to a max of 75 (the speed limit). And as the road flattens out I let the speed drop until reaching the base speed. This is called driving with load (DWL). Oh and yes, I had the a/c on.
  11. MaxxMPG

    MaxxMPG Hasta Lavista AAA-Vee Von't Be Bach

    Welcome to CleanMPG!

    Don't worry about being flamed - consider the logo on the top left corner of the home page. Read the slogan - "Learn to raise fuel economy and lower emission in whatever you drive" - and that includes a Crown Vic. If you were to join and say, "I need to buy a commuter car for my inner city dash from home to work from light to light and I want to buy a Crown Vic because they're cheap", expect some gasps of disbelief. But you already have the car, you want to keep it, and with some commitment, you will beat the heck of the EPA with it. And that's better than selling it to someone who is going to do the Sousa-march on the accelerator and brake pedals and get 10 or 12mpg out of it. The car already exists, it's running well, you own it outright, and it does fairly well on the open road, so use it for its intended purpose. Drive it within city limits and it's gonna hurt bad, but I'm sure you already know that!

    The EPA numbers for the Crown Vic 4.6 - 18/25 and 20 combined, under 1985-2007 adjustment.
    Raw dynamometer numbers - 19.7 city, 32.3 highway, 23.9 combined.
    A good starting goal for highway mpg is to meet and then beat the unadjusted (dynamometer) number. That'd put you at just over 32mpg.
    From there to 40mpg is a long stretch, but stretch goals are what motivate us to improve.

    - Consider a ScanGauge to display engine parameters while you're driving. TPS, LOD, RPM, and instant MPG are good settings to start with.
    - Not sure if your car has fuel cut, but the SG will show you for sure (assuming it's set up properly). The transmission in the CV has a funky split-torque design with no true lockup, so I am not sure they could get fuel cut included - especially below fourth gear where all input power is through oil only, with no mechanical coupling.
    - If you need tires any time soon, look for tires with the lowest rolling resistance, choosing the narrowest tire that has the necessary load rating. Tire pressure setting is a highly personal decision, but I know some people who run tire pressures somewhere above sidewall, and there is a measurable difference in FE, up to a point.
    - On the highway, the best speed for the car is going to be in the 45-55mph range. If you must drive 60 or higher, throw the 40mpg goal out the window - ain't gonna happen. Time and money are interchangeable, so saving time with higher speeds is going to cost money. Spend some extra time and you will save money. That's Newton's Fourth Law of Relativity, not to be confused with his Fifth Law, which involved using his own last name to christen a gooey fig-paste cookie he invented.

    I don't believe that coasting in neutral will hurt the 4R70W transmission, but you will want to keep the engine running when the car is moving. I think these automatics can roll at up to 30mph with the engine off, but don't quote me on it and you'd want to consult the owners manual under "recreational towing". Unless you have low rolling resistance tires, I suspect that bumping the lever to neutral is going to cause a rather sudden loss of speed, and when bumping back to D, the trans will return to third and then shift back to fourth, wasting fuel while it dawdles around trying to get everything applied and locked up. To keep things simpler, go for the low hanging fruit - more air in the tires, lower road speed, ridge riding and taking advantage of traffic side draft as the speeders zoom by in the next lane.

    And don't be a stranger. Read Beating the EPA and ask lots of questions, and never give up. Even if improvements are minimal, understand that they are usually small at first but they keep coming as the various techniques become part of your daily drive.
  12. 73VWTodd

    73VWTodd New Member

    Wow! Thanks guys! I hadn't gotten any "Message Reply" e-mails so I just assumed the thread wasn't getting any responses!

    Thanks for all of the replies!!!

    I've got a lot of reading to do I suppose since I have no idea what FE is and I've seen it mentioned a few times.

    Yeah, I've run into issues with tires before. The tires I have on there now are Goodyear Comfort-tread which I bought solely because they were white-walled tires, and I wanted to keep the car original looking. That said, they were "decent" tires for fuel economy since they were pretty quiet and compared to what else was out there, they had a lower rolling resistance (according to TireRack).

    I ran into issues with my Explorer a couple of years ago. I had normal all-weather light-duty pickup truck tires on them, and I replaced the tires with "V" treaded tires for better wet adhesion. In South Florida, it rains a lot, and thought that would be a good switch. While my wet-weather driving was substantially improved, the fuel economy took a nose-dive. So I realized immediately after that, that directional tires are NOT what I want for fuel economy!

    Man, there's a lot of good info on here. Next time I plan a trip to Orlando, I'll try it at 65.

    Can someone explain to me why I want the engine "loaded" in lower RPMs, and why that produces the best fuel economy? I had always assumed that if the engine was at the point where the horsepower and torque numbers typically meet each-other on the dyno-graph (for whatever that would represent) that this would be the most optimal location... IE: lower rpm, but higher horsepower which denotes better engine efficiency at that RPM, and then of course, decent torque. But none of that subjective reasoning I've come up with has any scientific basis! hah...

    As for coasting... my Crown Victoria has a really, really heavy flywheel. Florida is flat... so if I'm cruising down a long stretch, and I'm going at about 45mph and take my foot off the gas... the car will just continue to go for what feels like forever.

    Oh! Couple of other questions. Some other thoughts I had to improve fuel ecomomy / efficiency that I would like to run past you guys:

    1 - Underdrive pulleys: I was thinking of getting a set, specifically ones that reduce the belt ratio from the crank, and also the alternator.

    2 - Driveshaft: I currently have a steel driveshaft (all non-police ones do). The aluminum, and even metal-matrix ones are supposedly substantially lighter (like 22 down to 8 pounds). They are also better balanced, and supposedly can handle higher speeds for whatever that's worse. I'm sure this will improve acceleration, but will this improve fuel economy? My first thought is that less rotating mass will mean less effort to make it move, but then I figure inertia on a heavier drive-shaft will help it keep moving? Any logic to that?

    3 - I have Redline 5w-20 in the car now, but I have not yet swapped out the fluid in the crank-case. I have swapped out the transmission fluid, and I believe I used Ford compatible Redline fluid as well. I had meant to do the differential, but just haven't gotten around to it. So I'll take your guys advice on that and try to get that done as soon as possible too.

    4 - They also have some underbody skirts that they sold a while back, and I can't find them now. They're essentially under-belly trays that are supposed to help aerodynamics. I'm going to try to see if I can find those again, and buy them.

    5 - As far as alignment... I've taken the car to the shop a few times for alignment (everything else, I do myself). A few times, I've noticed they've set it up with the wheels splayed outwards... which seems absurd to me. I don't know why they can't just set it up with them both facing perfectly forward. For the record, the tie-rods are NOT EVEN IN THE SLIGHTEST BIT worn out... I just don't think they know what they're doing. The last time I took it in, I showed them and they fixed it... but it's still not what it should be. I'll probably take it in to the dealership, rather than TiresPlus to have them fix the alignment.

    Anyway, thanks again guys, I really appreciate it.
  13. The Doctor

    The Doctor Old Dude, New Car

    Welcome to a Floridian, from another Floridian!

    I got a ride in a Crown Vic once. The only drawback was the bars on the windows. :D
    That does detract somewhat from the Ambiance.

    Seriously, that is a beautiful car and not all that bad, aerodynamically speaking.
    Nothing like my Kia Soul (econobox).

    But things like tire pressure, air cleaner, weight of oil, transmission and gear box fluids, can all make some difference in your MPG.

    Remember, that when you turn on accessories, they are all powered by 'gasoline'.
    On my car, when I'm cruising down the highway and turn on my AC, I can watch my mpg drop by as much as 3 mpg, as seen on my Scan Gauge II.
    The drop will probably be less on a car with a V8 engine, but it's still there.

    On my last car, the Suzuki SX4, AWD, I added 10% Prolong Gear Lube to my transfer case and differential, when I did the fluid change and saw a nice increase in performance.
    I also used Prolong in my AT and engine, again for a nice little increase in performance.
    Reduce friction and everything runs cooler and lasts longer. Just basic mechanics.

    Good luck hypermiling the Crown Vic.
    I would take that as a challenge.

    Cheers mate!
    The Doctor :cool:
  14. phoebeisis

    phoebeisis Well-Known Member

    Usually swapping components-driveshafts-lotta work-little payoff in
    FE Fuel Economy.
    Now it will improve performance-maybe not enough to measure-but the car will be a tiny bit quicker.
    Lighter wheels-forged aluminum alloy centerlines 17" 7.5 were 5 lbs each less than the stock cast aluminum alloy OEM wheels on my Titan pickup-and 10.5 lbs less than OEM steel
    $600-probably helped acceleration-with a tiny-not measurable improvement in FE
    Yeah-lighter weight improves city FE-but tough to measure.
    Nothing you can switch bolt on will improve FE as much as modifying technique.

    If you can get the driveshaft cheap AND it isn't tough to switch-have at it.
    I usually find that easy switches-aren't so easy-always some "problem" that crops up.
    Maybe with the Crown Vic-it IS an easy swap.

    Oh-if the Crown Vic WAS CHEAP TO BUY USED- I would consider it for city driving commuting-if it was also easy to DIY repair.
    If you are short of funds-sometimes it makes sense to buy a poorish FE vehicle-because it has other desirable qualities-cheap to repair-reliable-lots of carrying volume.
    Usually it isn't-but sometimes it is.

    I suspect Crown Vics aren't cheap to buy-used-anymore.
    Lotta folks LIKE the V-8 RWD big comfortable nice looking reasonably quick
    and cabbies used to LOVE used CVs-so there is too much demand for Crown Vics now that they aren't available anymore-and cops and cabbies have run the wheels off lots of them !
  15. ItsNotAboutTheMoney

    ItsNotAboutTheMoney Super Moderator Staff Member

    TLDR: automatic transmissions are inefficient, so you have to trade some engine efficiency for transmission efficiency

    Here's how I understand it:

    With a manual transmission you have an efficient transmission (hard connnection) and you control the gearing. So you can pulse at peak-efficiency to your hearts content in your top gear. But then, because sustaining that peak efficiency will cause your car to accelerate to a high speed you start suffering from increased drag. So, you don't suffer from too much drag you let off and in order to minimize drivetrain drag you put the car into neutral and glide. Ideally, assuming the transmission can take it (and many/most manuals can) you turn the engine off so that your "glide" consumes no fuel. That's the essence of P&G (Pulse and Glide).

    But, like most Americans you have an automatic transmission because it makes driving easier. Unfortunately, because of a history of cheap gas US automatic transmissions sacrifice efficiency for a smooth feeling. They achieve smoothness by not have a physical connection and instead use hydraulics. This is inefficient. So, modern transmissions added a "lock", a clutch, which allows for a more efficient physical connections under certain circumstances where the risk of stall is very low and the driver is unlikely to need a sudden burst of acceleration. In the typical "slushbox" automatic, the inherent inefficiency of the transmission means that a key to efficiency in a modern US automatic is keeping the torque converter locked, which means maintaining a moderate load in a high gear. That's the essence of the benefit of DWL (Driving With Load). But Chris noted that your transmission doesn't lock well anyway. Either way, transmission inefficiency in an automatic sucks under load so what you'd gain with peak efficiency on the engine you'd lose to inefficiency in the tranmission.

    So, given your car is a boat and the transmission doesn't lock well the idea is simply to keep engine RPMs down while staying in your highest gear. It's just a matter of trying to make it as easy for the car to do that. Given that you're in Florida that means flat ground and flat ground is great for efficiency. If you can keep your speed down, ideal, if not you just work on the other things that make your car use more gas, starting with the waste from poor maintenance, unnecessary braking (fixing the nut behind the wheel), excessive rolling resistance and vehicle weight. If you plateau and want to go crazy then you can look at making aerodynamic tweaks.
  16. some_other_dave

    some_other_dave Well-Known Member

    The torque and HP curves always cross at 5250 RPM. That's because HP is torque * RPM / 5250 (if you measure torque in lb-ft).

    If you google up BSFC or Brake-Specific Fuel Consumption, you'll see that you typically generate more power per unit fuel burned at lower RPM and a more-open throttle. The whys of this are a bit complex, but they have to do with how easily you can draw air into the cylinders, how that affects the burn, and not telling the engine management system (or carburetor) that you're trying for all-out acceleration.

    The short version is that most engines seem to operate most efficiently at about 80% throttle around 2000 RPM. But usually that will make the vehicle accelerate (if slowly in many cases), so that doesn't help much for steady-state cruising. For cruising, you get the car in its top gear and keep your throttle very steady.

    They can help a bit, but the payback in fuel cost is usually a long time. Also, if you decide to keep your engine at very low RPMs all the time, you may wind up under-charging when you put a heavy load on the electrical system.

    It should help, but chances are it won't be enough to measure. The pay-back period for any fuel savings just from that mod probably exceeds the useable life of the car.

    Belly pans can help air flow around and under the car. If they're cheap enough, the pay-back period can be reasonable. The folks over on http://www.ecomodder.com often use "coroplast", corrugated plastic that is usually made for signs. You can find it very cheap just after election season, but you may have to paint over what's already on it. ;)

    They help more at higher speeds, as do any aerodynamic changes.

    Sounds like toe-out, which doesn't make any sense at all! Some FWD cars are set up with toe out in front because the drive wheels will tend to pull the wheels into toe-in, but RWD cars should not be set up that way. It will tend to make the car feel "twitchy", and want to change directions very easily. It will also tend to wear the front tires on the inner edges.

    Here at cleanmpg, we tend to focus on "tightening the loose nut behind the wheel". You can get very significant improvements by changing driving style. Over at Ecomodder, they tend to focus more on vehicle modifications. Those are generally much less effective, until you get to cars like Basjoos' AeroCivic.

    The number one thing you can do for your MPG is to slow down. Try setting the cruise for 60 MPH instead of 70. Better yet, train your foot to keep absolutely perfectly still and keep the car right around 60 MPH. Cruise control tends to vary the throttle more than you would think, and it is more efficient to keep a steady throttle setting.

    The number two thing you can do is get some instrumentation. If your car has its own MPG display, you can use that. Most of us like the ScanGauge II, which plugs into the OBD2 port in 1996 and later vehicles. Instant feedback on your driving style can be very useful in improving your fuel economy.

    Last edited: Apr 1, 2013
  17. herm

    herm Well-Known Member

    perhaps he means negative camber?
  18. RedylC94

    RedylC94 Well-Known Member

    Very good answer from some other dave!
    I would add:
    Underdrive pulleys might also risk abnormal hot spots in the engine if the water pump is driven too slowly.
    33,000/2pi = about 5252.
    The main reason gasoline engines are inefficient at light loads is that the engine has to do a lot of work just sucking its air past the restriction of the mostly-closed throttle. Also, reducing output torque means a higher percentage of energy is lost to frictional torque (which is relatively constant, regardless of load).
  19. EdwinTheMagnificent

    EdwinTheMagnificent Legend In His Mind

    And the Stoners sit between the Jocks and the Nerds.
  20. PaleMelanesian

    PaleMelanesian Beat the System Staff Member

    Here's the best article about Brake Specific Fuel Consumption. It explains how/why the low rpm / high load mode is best for fuel consumption. It's easier to target the ideal spot with a manual but do what you can with an auto.


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