Subtopic	Posts		Updated
	Gas Mileage increase, a suggestion.	9		05/08 09:15pm

By rob gaspar on Thursday, March 15, 2001 - 10:43 am: Edit

Without sounding naive, should I be getting better than 12 mpg for mixed city/highway in my '97 ? Would changing the plugs or using a gas additive make any difference ? Thanks

By Ron on Thursday, March 15, 2001 - 10:57 am: Edit

If you have not changed your plugs and wires in the last 24 months I would do that. I am happy with 11-14 but that is in a heavily laden, very aerodynamically inefficient disco.

get wires at:

www.magnecor.com

Plugs NGK s or champions (some like the plus 4 bosche)

By Tom on Thursday, March 15, 2001 - 07:18 pm: Edit

12 mpg is bad. When is the last time you changed your air filter? For 7-10 bucks for a new paper you may get an addition 1-2 mpg. A K&N filter made mine go up a bit higher when new, but now that I have had it for a while and it seems impossible to get it cleaned like new, I don't get any advantage over changing paper filters w/almost every oil change.

If anyone has any tips on how to get a K&N squeaky-clean, please respond!!!

Tom

By Nathan Crabtree (Nathan) on Thursday, March 15, 2001 - 07:38 pm: Edit

Rob
Contact me if you would like to get a K&N air filter. I put one in my Discovery and increased my mileage by 1.5 MPG.
Thanks
Nathan

By wes on Thursday, March 15, 2001 - 09:43 pm: Edit

Tom,

Are you using the K&N Cleaning kit?

wes

By Tom on Thursday, March 15, 2001 - 10:56 pm: Edit

Yep...followed the directions to the letter...maybe I am just oo picky. The thing is still "brownish" and there always seems to be more little dirt bits in it.

Tom

By Bill B on Friday, March 16, 2001 - 09:53 am: Edit

K&N recommends NOT cleaning their filters too often - supposedly work a little better once oiled and used.

By Alan on Monday, April 23, 2001 - 06:07 pm: Edit

Does K&N make an air filter for the Disco II? I can't seem to find it in the catalogs / web sites.

By herky on Monday, April 23, 2001 - 06:10 pm: Edit

yeah I got one last month, dont see any diff on mileage though, i have a 2k disco II with 10k miles and get about 260 per tank, a 24.6 gallon that sucks!I know I know its a rover but that is piss poor for 180 horses full time awd or not.

By Alan on Tuesday, April 24, 2001 - 03:16 am: Edit

OK herky, so where did you get your K&N air filter for your Disco II?

By Jon on Tuesday, April 24, 2001 - 04:06 am: Edit

Yeah, don't clean your filter too often. Every 50,000 miles is the lowest recommended cleaning mileage, even for dusty, dirty driving environments. Usually they only need cleaning every 100,000 miles. And the dirtier they are, the better they filter, believe it or not. Even a filthy K&N filter is loads less restrictive than a clean, new Rover paper filter. But 12 mpg in mixed driving is a little low (unless you just have a heavy foot). I usually average 15, but have gotten upwards of 19 in continuous highway driving (and yes, I have a K&N filter in my '95 Disco). It sounds like a tune-up would help your mileage. Oh, and regular unleaded will shoot your gas mileage, so you can only get your best mileage with Premium. However, Amoco and Mobil mid-grades seem to work as well with no noticable decrease in performance.

By pjkbrit on Tuesday, April 24, 2001 - 04:19 am: Edit

Clean that filter with the cleaning kit and a decent hose from the inside out...mine comes up totally clean each time...and I clean mine about every 25K which is probably too often!

By herky on Tuesday, April 24, 2001 - 04:50 pm: Edit

My rig only has 10k do you think it needs atune-up? I just took it in for its 7500 mile maintanence, wouldn't they check this? This is my first disco and i wouldnt trade it for anything but you guys post way better mileage than me. I had autozone order my filter took aboutt 3 days. I am not heavyfooted because we wont go anywhere real fast anyway. and i have always used premium,on all my vehicles. I am just concerned because gas is supposed to go up again this summer.

By gtx on Tuesday, April 24, 2001 - 06:03 pm: Edit

Hi there
I live in england and run a 3.9 disco,petrol here is the equivelent of $5 dollars a gallon, just thought it might cheer some of you guys up.I was in the states last year and believe me if I had a waterproof suitcase it woud'nt be levi's I brought back!
Regards Gary

By pooley on Wednesday, April 25, 2001 - 05:44 am: Edit

I had a 94 3.9 and managed 15mpg round town with max of 20 on the highway, great car chaged to a 98 TDI and now get 30mpg on highway and 22mpg pulling a 17ft van.

By Joshua Bova (Jbova) on Wednesday, April 25, 2001 - 10:27 am: Edit

What the hell is wrong with my truck (95 3.9)?
I get a very consistent 10mpg. Here is a list of the things I've done in the last 2 months in an attept to remedy the situation:
New O2 sensors
New Spark Plugs
New Magnecore 8mm Wires
New K&N Air Filter
New Cap and Rotor
Some stupid ass "As seen on TV" fuel/oil/transmission additive "Guaranteed to increase mileage by 10%"

I have 3" of lift, 235/85 BFG MTs, ARB w/ winch, and a rack (though the rack didn't seem to affect the mileage).

Anything else I should try?
If anyone says diesel they loose a testicle.

-josh

By Tsiegwart on Wednesday, April 25, 2001 - 10:36 am: Edit

Josh,

Did you take into account the different tire diameter when calculating your mileage?

Todd, 95 Disco, 11-13 mpg

By Ron on Wednesday, April 25, 2001 - 10:37 am: Edit

Vacuum (my guess) and mechanical advance need to be checked. Not 100% sure how you do this on a 95 disco but it sound like this we would the next logical step. After that I would say worn engine/fouled valves tested with a compression tester, then I would guess coil if that is a possibility.

Ron

By Ron on Wednesday, April 25, 2001 - 10:39 am: Edit

PS the disco got 7mpg running on 6 cylinders toing 3000lbs with 1000lbs of gear.

Ron

By Jon on Wednesday, April 25, 2001 - 10:48 am: Edit

10,000 miles, huh? On a '97 model? Maybe you just need to get it used to running again LOL Take it out and drive it on the highway a lot. Your mileage should increase with time.

By Joshua Bova (Jbova) on Wednesday, April 25, 2001 - 10:51 am: Edit

Todd,

I was under the impression that 235/85 was actually the correct diameter and the stock tires are off. This information is second hand at best, but I have checked my speedo against those stupid little radar trailers that the police set up and it is very accurate. I suppose I could do a better test then that.

Ron,
I will check the the timing advance, that does sound like a good idea. I am not exactly sure how to do that either. But what else would I do on a weekend if I didn't have something on my truck to fix/investigate?

Thanks.

-josh

By Bill Gill (Bluegill) on Wednesday, April 25, 2001 - 11:50 am: Edit

Josh:
>New O2 sensors
>New Spark Plugs
>New Magnecore 8mm Wires
>New K&N Air Filter
>New Cap and Rotor
>Some stupid ass "As seen on TV" fuel/oil/transmission additive "Guaranteed to increase mileage by 10%"

You probably should have taken all the money you spent on the above items and put it in a savings account to pay for all the gas you're using...ha ha.

Seriously, all you additions, with the exception of the fuel additive, seem to be worthy investiments. Stay away from those additives - hell, you should stay away from TV too.

Remember that you've substantially altered your rig with 3" lift, different front fascia, taller tires, roof rack, more weight, etc. Before and after wind tunnel experiments would probably be surprising (all that tubulent air under the rig now). Of course, even stock Discos have high coefficients of drag compared to most cars.

Also, Tsiegwart brought up a good point with the tire diameter factor - larger diameter tire covers more distance than smaller (stock) with each revolution. But you're still using the stock measuring devices (speedo and odo) to gauge the larger tires. You're therefore going faster, covering more distance, and getting more miles per gallon than your stock instruments indicate. Grab a GPS unit and gauge your speedo yourself. Do it in 10mph increments on 3 separate occasions, perform calculations, take averages, and stick a little chart on your dash. You gotta be a real real gone Type A to do that, though...

By JEEPETR on Wednesday, April 25, 2001 - 12:03 pm: Edit

Hey Guys,

I don't know that everyone's speedo would be the same, but my 1996 Discovery read 10 MPH fast at highway speeds, with the stock Michelin 235/70-16 tires (Checked against a GPS). With 215/85-16 tires it reads about 5 MPH fast. I just tried out a set of 235/85-16 tires, and the speedometer was dead on compared to the GPS.

So, actually, it would seem that those on stock tires, or just slightly larger, are probably getting better mileage calculations than actual, as their odometers are recording more miles than they have actually traveled...

Suppose Land Rover does this to get them out of Warrantee quicker?!?

~Scott T.
'95 D-90 (JEEPETR)
'96 Discovery (New addition to the Addiction!)

By Bill Gill (Bluegill) on Wednesday, April 25, 2001 - 12:55 pm: Edit

> Suppose Land Rover does this to get them out of Warrantee quicker?!?

Sure wouldn't surprise me! I've heard the same thing about bad stock speedo calibration from others...

The important thing here is the net change or shift, as regards tire diameter and apparent or real mileage calculations. Maybe stock calculations were erroneously optimistic, maybe aftermarket tires give falsely pessimistic calculations. The speedometer gives a relativistic frame of reference...the facts dictate that larger tire travels farther in one revolution than smaller tire, no matter how you measure it. No you've got me thinkin...I'll have to boot up the GPS tonight and check my speedo against my new 245/75's...

By s. holden on Monday, May 07, 2001 - 08:46 pm: Edit

wow! I get 370 miles out of a full tank, so am guessing at 18mpg. After reading all your mpg, I'm not sure what mine does different. I'm only using mid grade gas too, not premium. It's mostly freeway driving, but there is a fair bit of town driving in there. I did recently put a new K&N Air Filter since everyone was recommending this on this board, but was getting this mpg before I put it in anyway. I use cruise control a lot when freeway driving and that might make a difference and usually drive at about 70 tops. I do put engine cleaner in every 4000 miles and use synthetic engine oil, but apart from that, dont use anything special.

By gil on Monday, May 07, 2001 - 08:53 pm: Edit

is that a Disco 1 or 2? The D1 tank is 15.5 gallons, the D2 is 24.6, that may have something to do with it. If I were you, I would be very happy that the Rover gods are so kind to you.

By Axel Haakonsen (Axel) on Monday, May 07, 2001 - 09:14 pm: Edit

You are thinking of a D90. The Disco 1 tank is 22 gallons.

By gil on Monday, May 07, 2001 - 09:35 pm: Edit

thats right, my fault.

By italian on Monday, May 07, 2001 - 09:37 pm: Edit

I have actually put 24.2 in my Disco I.
Yes...running on fumes. (also accounts for the filler tube)
My mileage, for the comparison is usually 7-19 with 2/3 highway per tank (includes rush hour in Denver).
Running 91 octane, K&N.

By Scott H on Tuesday, May 08, 2001 - 01:32 am: Edit

I get 11 no matter what I do, 80 on the freeway, wandering around town...in a head wind...11. I put new plugs, new wires, K&N air filter, had the lube in transfer case changed to synthetic, have the engine running synthetic, had the lube in the axles changed...11. Ah well, at least its consistently sh*ty gas mileage..

By Jon on Tuesday, May 08, 2001 - 09:37 am: Edit

My thoughts exactly. After taking into account a slight speedomoter/odometer error, and recording my mileage over the course of a month, with mostly highway driving at or under 70 mph, and a bit of town driving, running a K&N filter and using Mobil 1 synthetic oil, burning either Mobil Super+ or Amoco Ultimate for gas, my truck averages a consistant 13 mpg city/17 mpg hwy. Just as the window sticker said when it was bought in 1995. But it's not too disappointing, given the fact that there's a not-so-hot 3.9-liter V8 constantly driving both axles on a 4400-pound vehicle, so I don't complain.

By Bill on Tuesday, May 08, 2001 - 10:47 am: Edit

Back in college I drove a Nissan Pickup, stock except for 32" tires and aftermarket wheels. That thing got 16-17 mpg, and I loved driving all over in it. I now live in the middle of friggin' downtown Chicago, driving a honda civic, getting around 26 mpg. What I wouldn't give to speed up 10 months time (when I move outta here) so I can get rid of this "economy box", and buy my inefficient Disco II! I am sure I'll complain about the crappy mileage too...but it will take a while.

By J on Tuesday, May 08, 2001 - 02:55 pm: Edit

18+MPG!!!
I just drove from Boston to NC, to Shenandoah Valley, the Poconos, Catskills, and Berkshires, & back home. I noticed down south my heightened mileage and attributed to the flatness, however, I still got 18+Mpg back home. The reason? Down south in Nowhere'sville -- everyone drove the speed limit. Keeping under 70 (unwillingly) is what got me incredible mileage.
Last oil Change, I added Slick 50 AND a lil silver Valvoline "6,000 mile" additive as well.

By Joshua Bova (Jbova) on Tuesday, May 08, 2001 - 03:23 pm: Edit

After more extensive tests designed to measure the accuracy of the odometer, I have determined that my odometer/speedometer is dead on. This dead on is with the addition of 235/85 MTs and no recalibration. Therefore all of you out there with stock size tires, you are getting worse mileage then you think, going slower then you think, and reaching the end of your warranty faster then you should. 3 cheers for LRNA.

-josh

By pk on Tuesday, May 08, 2001 - 03:35 pm: Edit

For mileage to improve on a 94 or 95 NAS Disco you need the following.

-Some good spark plug wires.

-Some kind of platinum spark plugs. (I like Autolite AP65s) Also, the correct gap is critical to mpg. If you are serious, you can play around with the gap to maximize mpg.

-K&N air filter. The cone shaped filters should be even better for mpg but not if you wade in deep water!

-Tire pressure 34 psi front, 42 psi rear.

-Timing. Timing and spark advance is crucial for good mpg. As I recall, it should set to 6 degrees BTDC at less than 800 rpm with the vacuum hose removed from the distributor. Then, with the hose reattached, it should jump up and advance to that big deep groove on the pulley at about 3000 rpm.

-imagine there is an egg under the gas pedal and try not to break it with your foot. hehehehe

pk

By Jon on Tuesday, May 08, 2001 - 03:49 pm: Edit

I don't know if I agree with the platinum plugs part. They require a very high-energy ignition system, which Lucas does not make. I've had better results using properly-gapped plain 'ol Champion plugs than I have with premium-priced platinum tips.

By Joshua Bova (Jbova) on Tuesday, May 08, 2001 - 05:08 pm: Edit

I would also qualify the air pressure statement with tire size and suspension. PK has a stealth disco where as mine is obviously modified, I am running 3" of lift and 235/85 MTs. If I were to run the suggested air pressure, mileage would be a moot point as I would no longer be able to drive my truck in a straight line.

I am unqualified to argue the accuracy of Jon's post concerning the plugs, but if he is correct, then one way to boost the efficiency of your ignition system is with some Magnecore wires. I replaced my stock wires with 8mm Mags and was pleased, seems to run smoother but no increase in mileage.

Back to PK, dead on with the timing comment. This is very important and the egg under the pedal is indeed a factor as well.

-josh, wishing he didn't crack the egg as often

By Jinwoo on Tuesday, May 08, 2001 - 08:22 pm: Edit

PK, according to the manual, the tyre pressure for front is 26 and rear is 34 psi.
You mentioned 34 psi front, 42 psi rear and is it way too high? Basic physics says you get more milege if you have more air in your tyre and I'm wondering what's the best tyre pressure for normal driving.

Jinwoo
95 Discovery with 13~14 mpg.
Tyre pressure for front is 28 and rear is 36

By Blue Gill (Bluegill) on Tuesday, May 08, 2001 - 08:25 pm: Edit

I'm running 66 front and 60 rear - still playing with pressures, but this seems to make truck handle the best. I'll have to check wear pattern on tires with chalk line test, though.

By Huh? on Wednesday, May 09, 2001 - 08:00 pm: Edit

66 front 60 rear?

Gee I hope your tyre dealer is close by, you just reduced your tire life by 60%

Methinks Blue Gill (Bluegill) is bullshit artist?

By Blue Gill (Bluegill) on Wednesday, May 09, 2001 - 08:05 pm: Edit

Tires are 10-ply load range E with 80psi max pressure. I'm a scientist, not a bullshit artist. Where did you come up with your precise 60% tire life reduction assessment?

Take my advice and change your name to Duh?

By Ken on Thursday, May 10, 2001 - 01:22 pm: Edit

My 265/70/16 was more worn on each side, and not the center. I inflate the front and rear pressure to 40psi to wear the middle some more... I guess i am just cheap. I am running 38psi, and it seems to wear evenly.

my 2 cents
Ken