Gas Milage (merged threads)

[jrmark8]

The car is running 17.2 miles per gallon on highway. what can i do to bring the miles up a little higher.

[Icarus]

Tune up (air & fuel filter/plugs/pcv/etc), pull codes to see if theres any set...
Running wheels that are not factory sized may confuse the readings, same with gears...

[ekooke]

The car is running 17.2 miles per gallon on highway. what can i do to bring the miles up a little higher.

Easiest thing to do is make certain tires are properly inflated; I run 32 psi F/R. At a steady 70 mph in OD, you should be around 1700 RPM on the tach, and averaging 27+ mpg.

[pro-five-oh]

Jeez, you should be getting 10MPG better than that! Are you running in overdrive?

[JoshMcMadMac]

You haven't told us about the car, though. Does it "feel" right? Are there any noticable issues? Does it have five million miles on it? Does the transmission work smoothly? Have you done anything to tune it up?

[jrmark8]

You haven't told us about the car, though. Does it "feel" right? Are there any noticable issues? Does it have five million miles on it? Does the transmission work smoothly? Have you done anything to tune it up?
It has 97000 miles on the car, Transmission feels fine It it shifts with no problem, I always drive with O/D "ON" but sometimes in the city it's off. and soon will be doing tune-up within a week or so.

[NYC LS8]

When was the last time the fuel filter was changed? That'll make a big difference, as well as plugs, wires, air filter, etc.

[youbetcha77]

Will a fuel filter have much affect on mileage, if it isnt starving or anything. Mine looks original, but the car runs perfect. Mileage isnt what it should be on mine and it has had all the tune-up stuff done with no codes. I was just wondering about the filter thing.

Blaze

[jrmark8]

When was the last time the fuel filter was changed? That'll make a big difference, as well as plugs, wires, air filter, etc.
Changed the fuel filter sometime in august of 05 PIA to get that clip off. i changed the air filter which is a K&N around the same time.

Ijust need to do a tune-up like new plugs and wires I'll see what happens from there on

[NYC LS8]

Mine ran fine, too, when I picked it up. When I took the old filter out I tried blowing through it...I think I turned blue in the process.

[Patch It 86TC]

Hi,
I've another suggestion that wasn't mentioned above. Some say "This engines cooling system is terrific,Shes running SO cool,shes hardly Warmed up after driving her hard!!"

IF your 'TEMP' is low replace the thermostat. The sensors will tell the 'puter to keep the fuel rich until shes warmed up & blow your milage! Should you need to replace it go for one of QUALITY,don't skemp here, and make sure its OE TEMP range. HTH Wallace

[Shrewsbury]

The thermostat is an very good suggestion. You're about the place in your car's history where it could fail open. It's also a cheap and easy change, and probably needs to be done anyway. Remember that a hotter engine is a more efficient engine.
Also, you mentioned the K&N filter. Perhaps you've oiled up your MAF elements with the aftermarket filter? Clean the MAF; Dereck authored an excellent tech article (http://www.lincolnsonline.com/tech/00059.html) on how to do it.
Keep us posted!

[JoshMcMadMac]

Gooo, isn't the thermostat a royal pain to change on the VIII's?

[NYC LS8]

Only because there's like 4 hoses that go into the housing and nothing holds it in place except those hoses. Oh, and steel bolts into aluminum housings like to seize. Just gotta be very careful not to snap the bolts if they don't want to move.

[Dereck]

The car is running 17.2 miles per gallon on highway. what can i do to bring the miles up a little higher.

Hi JrMark8

Damn you need to get yourself a 92 Town Car mine does 76mpg on the freeway and about 57mpg around the city.

Regards

Dereck

[jrmark8]

Hi JrMark8

Damn you need to get yourself a 92 Town Car mine does 76mpg on the freeway and about 57mpg around the city.

Regards

Dereck
DAM! I HEAR YA, Maybe one day I'll get a town car, nah I love my mk8 too much

[jrmark8]

Gooo, isn't the thermostat a royal pain to change on the VIII's?
the answer is YES also it could be messy at times.

[John M. Courcoul]

Not wishing to make the oil companies any richer but unwilling to lose performance, what would you recommend be done to improve gas mileage on a '95 VIII with 77,000 miles on the clock?

I've already done the following:

- Cleaned the EVR filter as per the Tech link.
- Cleaned the MAF sensor as per the Tech link.
- Changed the plugs with Bosch Platinum+2
- Cleaned the injectors on a test bench
- Changed air/oil/gas filters
- Changed the CID sensor
- Repaired/recalibrated the air suspension

And will do the following in the coming weekends:

- Change the tires (Michelin MXV4 Energy+)
- Clean the IAC assembly

Anything else I may be missing and that could yield an improvement?

[DaKat]

What is your current mpg?

[NYC LS8]

Don't bother trying to clean the IAC. Take it from someone who removed and replaced his in his old 95 twice. If you're gonna go through the hassle of yanking it out, at least replace it with something new. If the car isn't giving you idle problems, just leave it for now.

[John M. Courcoul]

It used to do 18 MPG city and up to 21 MPG highway. Now it is doing 14.9 city and I haven't taken it out on a long enough drive to get an accurate highway reading.

[ekooke]

It used to do 18 MPG city and up to 21 MPG highway. Now it is doing 14.9 city and I haven't taken it out on a long enough drive to get an accurate highway reading.

Something wrong there; even an LSC (3.27 rear) should get 25+ mpg on the highway. Try putting some air in the tires.

[Sysanalyst]

How old are those O2 sensors? They provide STFT info to the PCM which would affect fuel economy. Not a MK VIII owner, but this improved MPG on a big old Town Car.

[John M. Courcoul]

How old are those O2 sensors? They provide STFT info to the PCM which would affect fuel economy. Not a MK VIII owner, but this improved MPG on a big old Town Car.
You know, I was thinking of them, being the originals. I'll put them on the 'to change' list, thanks.

[John M. Courcoul]

Something wrong there; even an LSC (3.27 rear) should get 25+ mpg on the highway. Try putting some air in the tires.
25+ ? That would be nice... Tires have always been at 35 PSI, 5 over the recommended, plus I'm putting new rubber this coming weekend, cause the current ones are pretty cracked from the bad roads. Not to mention that the rainy season is starting and wouldn't want to hydroplane with a heavy car.

[John M. Courcoul]

Don't bother trying to clean the IAC. Take it from someone who removed and replaced his in his old 95 twice. If you're gonna go through the hassle of yanking it out, at least replace it with something new. If the car isn't giving you idle problems, just leave it for now.
Cool, cause I wasn't too keen on the knuckle bruisin' exercise. Idle's pretty even now, changing the plugs cleared a slight hint of misfire it had.

Please, keep them great ideas coming... :)

[pro-five-oh]

Replace soft and cracked vacuum lines. Big trouble spots are the PCV lines, the "T" at the back of the intake manifold (HELP! makes the replacement) and the hose between the intake tube and the passenger side valve cover.

[John M. Courcoul]

Thanks, I'll yank the beauty covers, air intake and go a-hunting for bad hose. Probably be a good time to change the PCV valve as well, it's already 3 years old.

[UDL]

It used to do 18 MPG city and up to 21 MPG highway. Now it is doing 14.9 city and I haven't taken it out on a long enough drive to get an accurate highway reading.

Take it out and do an "Italian Tune-up".

Don't go by the information center mileage. Measure the fuel used against the odometer readings.

[UDL]

25+ ? That would be nice... Tires have always been at 35 PSI, 5 over the recommended, plus I'm putting new rubber this coming weekend, cause the current ones are pretty cracked from the bad roads. Not to mention that the rainy season is starting and wouldn't want to hydroplane with a heavy car.

Also, the wider the tire, the more drag it will have.

[John M. Courcoul]

Take it out and do an "Italian Tune-up".

Don't go by the information center mileage. Measure the fuel used against the odometer readings.
Ha Ha... :cool: Heard they were doing many of those to the big gas guzzling SUVs lately.

But you do have a point. The mileage numbers I mentioned were taken from the information center so they should be taken with a grain of salt.

[John M. Courcoul]

Also, the wider the tire, the more drag it will have.
Stock standard factory original Michelin MXV4 Energy Plus 225-60/R16. Same as when it had better mileage, so I guess we can count these out.

[John M. Courcoul]

Another thought: how about reapplying Slick-50 Teflon oil treatment? Back when the car (and I) was younger, I put in the Premium treatment that was supposed to last something like 50,000 miles. Doing the math, that's pretty much over.

Pros/cons?

[ekooke]

Another thought: how about reapplying Slick-50 Teflon oil treatment? Back when the car (and I) was younger, I put in the Premium treatment that was supposed to last something like 50,000 miles. Doing the math, that's pretty much over.

Pros/cons?


Putting Teflon in the engine to improve mileage (or anything else) is just wishful thinking. The US government made the makers of Slick-50 stop all those claims years ago, and tests by car magazines show zero mileage improvement using this stuff, and even HARMFUL NEGATIVE things in the form of increased engine heat, caused by increased friction, as the Teflon turned to sludge (like "Black Death" in the AC) over time.

[UDL]

Stock standard factory original Michelin MXV4 Energy Plus 225-60/R16. Same as when it had better mileage, so I guess we can count these out.

That's a pretty good tire to use. I had them on both my Marks and still do on the '96

[John M. Courcoul]

Thanks for all the good ideas. Some are done already, for example, the vacuum hose between the intake manifold and the valve cover was really toast (literally). I'm still pending on the O2 sensors, which I will get in next weekend, after I find the darn right sensor. The car feels peppier and mileage has improved even as per the information center.

As I went over the car with a fine-tooth comb, the rear shock mounts turned out to be fast deteriorating (surprise, surprise...), making them the fifth set. Are the adaptor plates they sell on eBay, that allow you to use standard Thunderbird shocks, any good? If I were to put those in, any specific shock you would recommend?

Thanks again to this wonderful community!

[luxuryrules]

This may sound like a silly question, but are you using premium? My dad tried a few tanks of 87 in the 95 and it lost 1.8 mpg (our calculations using the pump & odometer).

Additionally, use a set of Motorcraft plugs or Autolite 764s as those seem to be what these engines respond to best. Don't forget anti-seize!

Your initial post... CID sensor? Cubic Inches Displaced?

Also you may want to kick around replacing the plug wires. Use Motorcraft for those as well.

As for shocks, I've used Monroe SensaTrack, Gas Matic, and KYB GR2s. The GR2s are my favorite *but* that's because I drive in a spirited manner and they help keep the rear end in check. SensaTracks gave me the softest ride.

Oh yes, and have fun with the upstream O2 sensors :) They're fun to get at.

[John M. Courcoul]

This may sound like a silly question, but are you using premium? My dad tried a few tanks of 87 in the 95 and it lost 1.8 mpg (our calculations using the pump & odometer).

Additionally, use a set of Motorcraft plugs or Autolite 764s as those seem to be what these engines respond to best. Don't forget anti-seize!

Your initial post... CID sensor? Cubic Inches Displaced?

Also you may want to kick around replacing the plug wires. Use Motorcraft for those as well.

As for shocks, I've used Monroe SensaTrack, Gas Matic, and KYB GR2s. The GR2s are my favorite *but* that's because I drive in a spirited manner and they help keep the rear end in check. SensaTracks gave me the softest ride.

Oh yes, and have fun with the upstream O2 sensors :) They're fun to get at.

Yup, always 92 premium. With 87 regular it feels like an ox. Which is why I'm leery of the road trip I have to make up North to the U. S. of A. in July: in Mexico, premium still goes for $2.94/gal... :eek:

I just put in Bosch Platinum+2's, changing the old +4's it had previously (the 'zone was out of those, the guys there also said that according to their computer, this car did not use spark plug cables... :rolleyes: ). When I changed them, oddly, I found the ones in cylinders 2 & 3 completely loose, so I was real careful with the torqueing. Antiseize is a must and if you can't get any, an old mechanic's trick is to put a drop of engine oil on the thread and then sprinkle graphite powder on it, which gives you the same effect. I change the cables every 3 years or so, I'll try to see if a regular Ford dealership can get me a set; anybody have a part number so I can order that? Lincoln won't touch the car 'cause it is too old', only diagnostics, and Ford "can't get Lincoln parts...". AND you can't get Motorcraft stuff anywhere else, go figure.

CID is what the dealer called it when I took it for diagnostic, also known as CAM. The little doodad behind the steering fluid deposit that senses the camshaft swinging by. Original was really deteriorated, which contributed to hard starting whenever the car was hot.

Thanks for the tips on the shocks. The 'junk in the trunk' effect is getting to be annoying now.

As for the O2 sensors, I KNEW YOU'D SAY THAT (quoting Judge Dredd :cool: ).

[UDL]

I just put in Bosch Platinum+2's, changing the old +4's it had previously (the 'zone was out of those, the guys there also said that according to their computer, this car did not use spark plug cables... :rolleyes: ).

Get a set of OEM Motorcrafts and keep them handy....You'll be switching back soon enough. Trust me on that.:D

I wouldn't take what the parts pushers at Vatozone say as gospel either.

[yakdude01]

It used to do 18 MPG city and up to 21 MPG highway. Now it is doing 14.9 city and I haven't taken it out on a long enough drive to get an accurate highway reading.

That is just NASTY! I recently drove my 95 Mark VIII from Boston to Dallas, 1985 miles. It was loaded with over 600 lbs of my stuff, since I relocated. And it still averaged 27 mpg @ 65-75 mph. It just turned over 100k mi after I got to Dallas. Looking to perform a tune-up myself soon, since 100k is the recommended interval.

Not sure what's going on with yours, since I'm no technician, but it's definitely not good.

Good luck with the repairs!

[luxuryrules]

Exactly. I got 24mpg at 85+ on my way back from Little Rock. With the trunk fully loaded, back seat full of luggage, and a passenger.

The 'Zone guys are getting your 95 mixed up with a GenII Mark, which uses Coil On Plugs. Even still, they should have a listing for the boots, which can crack and cause problems anyways... bit I digress. The MC part number is WR5873. If there is an Advance in your area, they can get them. Thanks for the tip on the plugs, by the way - I never knew that.

When I get a better look at m 95 I'll see if I can locate the PS O2 sensor for you. I know I can see it on my 96 from beneath, but 96 is the later version of the header/downpipe setup so it isn't the same as 93-95.

Realistically, you should just get headers :)

Additionally, how are the plugs burning? Also, what are the possibilities of a clogged cat?

[John M. Courcoul]

Night and day.

That's the difference after putting in new Ford O2 sensors. The old ones were definitely shot. At first blush, the car feels much peppier and responsive. Tellingly, the idle RPM went down all by itself. The jury is still out about the mileage, since it is still too soon, but I'm sure there will be a significant change.

On the other hand, the engine is running about 10-15% hotter than before, as seen on the temp gauge as well as reported by a scanner (this covers, hence, both coolant temperature sensors), but still well within the normal range. This is probably due to the engine running leaner, which means better mileage. If this is true, this also marks an approximate timeline when the O2 sensors started going bad, which corresponds to when it started running cooler than usual.

I'll report how the mileage went after a couple of tankfuls.

[towncar1]

What kind of hwy fuel economy do you guys get? Do you run premium or regular? The reason I'm asking, is I'm looking for a "luxury" coupe that will be able to deal with a 75 mile daily commute. Fuel Economy is important, as well as reliability. I'm also considering a 95-99 Buick Riviera or possibly a Mark VII.

All Opinions Appreciated

Dave

[turborich]

I think that any of the cars you are looking at will do fine on the highway, My 1995 Lincoln Mark VIII gets pretty crappy mileage in the city with lots of stop & go traffic. On the highway I do much better. If a straight highway run I get upwards of 25 MPG. Maybe more like 27-28 MPG. Once you hit the streets it starts to suffer.

The Mark VIII is far superior to the Riv in my oppinion.:) The Mark VII is a nice ride as well!

[DaKat]

I can usually pull down at least 30mpg on the highway as long as I'm not bucking a big headwind.

[towncar1]

Well, that sounds good, but my next question is how reliable are Mk. VIII's in general? How many miles should a well maintained one go? Was any particular year better or worse than the rest?

Dave

[JP]

IMHO, the Mark VIII will rival any luxury sports coupe in the MPG department.

I'm also considering a 95-99 Buick Riviera or possibly a Mark VII.


You don't want to put a Riviera against a Lincoln, they're apples and oranges.

I have a Mark VII, well, more exactly, my son drives my Mark VII. :o I've always liked them. They were the more 'muscular' looking Mark and certainly a fine automobile. But again, not to be compared to a Mark VIII - the generation gap is huge. But finding a worthy Mark VII is getting tough. You can still find a nice sampling of Mark VIIIs - just be sure you look at several and carefully inspect for proper maintainance. If you want a really good buy - find one with suspension issues that otherwise has lived a pampered life. ;)

[DohctorSmith]

Am looking at a 98 pearl white lsc with very slight front end damage(paint scrapes on front bumper cover), 105,000 miles for $2000.00. Was curious as to what kind of highway mileage these cars got.

[luxuryrules]

High 20s, sometimes you might break 30mpg. Consider in your decision that you may need to use premium to achieve optimal fuel economy. Some Mark VIIIs take a serious economy hit on regular, some do not.

Highway mileage is not your concern, so much as: the blend door actuator, the rear neon taillight, HID headlights, and condition of the air suspension.

Good luck!

[DaKat]

Quite frequently over 30mpg highway here, and not on premium.

[Mark_0101]

will since its an LSC you have 3.27 gears instead of 3.07. I doubt you will ever get into the 30s with an LSC. You will get high 20s but thats pretty good when you look at it, almost 2 ton, and a V8.

[DohctorSmith]

I have a 90 LSC and love it but it is down with brake problems(accumulator, I think) and having a hard time finding someone I can trust to fix it her in Tulsa, OK. Have been driving my Ranger 4X4 4.0 and gas mileage(16-18mpg) is getting rough.

[turborich]

I have a 90 LSC and love it but it is down with brake problems(accumulator, I think) and having a hard time finding someone I can trust to fix it her in Tulsa, OK. Have been driving my Ranger 4X4 4.0 and gas mileage(16-18mpg) is getting rough.

My friend has a complrte mastser cylinder unit from a 1988 ford thunderbird turbo coupe. I am pretty sure this is the same unit as the 1990 LSC. You mat want to check though, anyways, he has sold the car & still has the complete unit. He would let it go for very very cheap, i'm talking around $20 bux probally plus shipping. Let me know if interseted.

Also if this is the same electrictronicly controlled unit, most auto shops do not know anything about them! I found this out back when I also owend a 1988 turbo coupe. You are better off finding someone from one of the VII boards like this one who is near your area.


As for the VIII, it sounds like a great deal, luxuryrules is correct about the other issues. You should look/check for them. $2,000 for a nice gen 2 MARK VIII seems like a sweet deal to me. save some pocket change for any repairs. I have owned my 1995 VIII for 3 years now & I have only had to do routine maintenance. Everything else has held up great & my oppinion of the car is excellent!

[luxuryrules]

Mark, Kat's critter is an LSC.

And that mileage is very impressive Kat!

[DohctorSmith]

As per the second post, what is the best way to check blend door actuator? If it works smoothly it's OK? And as far as air springs, look for sagging and crawl up under car and look for cracks?

[luxuryrules]

Blend door: I will defer to a GenII owner as I have no experience with this personally.

Air suspension: if it sits for a few days or more and does not drop, then you're ok. Drive it and make sure there is no Check Air Suspension warning, and make sure to get it up to highway speed to ensure that the lowering feature doesn't expose any cracks.

[mikemark8]

Since you are in Oklahoma, you probably will get decent gas mileage, lots of open roads etc-here on the east coast, mostly city driving, you'd get around 15-17 tops, that's with limited expressway driving. Keeping your foot out of it will make a difference, but if it is a runner, that's hard to do;)-good luck

[Mark_0101]

Mark, Kat's critter is an LSC.

And that mileage is very impressive Kat!

Well I didn't see that but Gen I usually get better gas mileage then Gen II. I have seen it on my Marks. I am sure if you reset the computer and drive on 60 MPH, you will get 30+ MPG. I am sure it would be alot different if you hand calculated that mileage. when I took my 93 Mark VIII on a road trip, I got 25.7 MPG (hand calculated) which I drove at 75-85 MPH. So If i drive on 60 MPH I might get 30+ I don't know.

[DaKat]

I am sure if you reset the computer and drive on 60 MPH, you will get 30+ MPG. If you drive 60 on the highway around here you'll get run over.

[turborich]

[QUOTE=mikemark8;679684] mostly city driving, you'd get around 15-17 tops


I agree with that statement.

[Duck]

Avg 15.5 for me

[Philip]

If you drive 60 on the highway around here you'll get run over.

now you MUST be talking about South Florida drivers, sounds like here.

As for economy, I've always averaged 14/15 with mostly city driving and 24/25 on the freeway.