By pjkbrit on Monday, July 02, 2001 - 04:20 am: Edit

pjk

By Leslie on Monday, July 02, 2001 - 07:53 am: Edit

Me too!!

Interstate run from NE Tennessee to Norfolk.... when I showed the wife the calculations, her jaw hit the dash. This thing does a LOT better on long hard interstate runs; around town I'm usually pulling just over 16. (16.3 is about my running average now)

Hmmmm.... need to pull the receipts and check the return trip, too... See if I did as well, or not as good. We'll see.....

By Phil Scott on Monday, July 02, 2001 - 01:41 pm: Edit

Okay, I'll bite. How'd 'ya do that?

I just got back from an all interstate 3000 mile "vacation" (a 10-day odyssey of family reunions) and even after I put in a new K&N air filter and new sparks... I topped out at 14.39 mpg. That's with both front and back a/c's running and cruising 75-85 all the way.

Phil '96 SE7

By dave on Monday, July 02, 2001 - 02:23 pm: Edit

I get 18-19 on the highway for extended trips as well. Crusing about 75-80 with AC on. Around town is not as good ;-)

By JEEPETR on Tuesday, July 03, 2001 - 03:54 am: Edit

Must be Nice,

Well you 18-19 mpg guys are the lucky few I think. My '96 Disco (5-Speed) is mildly modified (Ome H.D. Springs, ARB Bumper, X9 winch, 215/85 BFG Trac Edge Tires), runs all RedLine Synthetic Fluids, Magnacore 8mm Wires, K&N Panel Filter, and new NGK Plugs. My around town mileage is consitantly low 14's and long freeway trips rarely net me any better than 16.5 mpg. Must be nice...

~Scott T. (Lead foot I guess)
'95 D-90 (JEEPETR)
'96 Disco (New addition to the Addiction!)

By JEEPETR on Tuesday, July 03, 2001 - 04:38 am: Edit

Oh, and another thing guys,

Are you basing your Mileage numbers on the grossly inaccurate speedometer/odometer combination? Because if so, highway figures for mileage will show roughly 8-10 % more than the milage actually traveled, which will of course make the mpg numbers look better than they are. Just another thought, hope it doesn't burst anyones bubble....

eg. 330 miles on tripodometer, fill tank w/ 19 gallons = 17.36 mpg.

But 330 miles is 10% high with stock tires. So Actualy miles traveled would be 300, with 19 gallon fillup = 15.7 mpg...

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

By Stephen on Tuesday, July 03, 2001 - 04:54 am: Edit

You need to keep in mind that you have some pretty serious weight up front and not the most economical tires for the road, though.
Not that I'm knockin' that stuff - I'm heading in that direction too!

By Neil Flanagan (Electriceel) on Tuesday, July 03, 2001 - 06:10 am: Edit

"But 330 miles is 10% high with stock tires. So Actualy miles traveled would be 300, with 19 gallon fillup = 15.7 mpg... "

This is more accurate. I've experienced a 7.5% to 8.5% discrepancy between the odo and GPS. With 245/75's (6% over stock 235/70's) the odo is closer to accurate.

I consistantly get 13.8 mpg local and 16 mpg highway(using milage from the GPS, slightly less during winter with the 'oxygenated' gas in the Northeast, keeping a database since mile 1). With the roofrack, all bets are off! It gets 13mpg regardless of local or highway travel

We all are striving to get better performance out of our vehicles. Magnecore wires, Bosch Plat. +4 plugs, K&N airfilter, the list goes on. And we convince ourselves there has been a huge performance boost. I attribute it to that 'placebo effect' when you , for example, install that K&N (I know, I have one too!) and immediately feel that extra HP and bonus fuel mileage. The reality is there is minimal, mostly unnoticable benfit. However, I must admit, base idle and acceleration is much smoother with the Magnecore 8 wires(I have had the 8's and currently 8.5's on the 90 and have not not noticed a difference between the two).

To those who are recording 19 mpg, make sure you are rounding those numbers properly. I, just have a hard time swallowing that a V8i Land Rover is capable of getting over 18...without being towed...or drafting an 18 wheeler

Sincerely accepting the fact the Disco gets *hitty mileage,

Neil
94 D90 #1092
97Disco

By Blue Gill (Bluegill) on Tuesday, July 03, 2001 - 06:21 am: Edit

have to second the odo discrepancy factor - I used to think I was getting pretty good mileage (16+) until I checked with my GPS. Now that I have 245/75's, my odo is pretty much dead-on. My fuel economy is just dead - 11.4 mpg last check (around town with a little highway travel, but AC on full blast full time to combat the 114 degree heat). My stock plugs and wires are only 7k miles old, and I run K&N air filter (did notice a very slight 2nd & 3rd gear acceleration boost with the K&N). The verdict: fuel economy is an oxymoron when talkin Disco's

By jcw on Tuesday, July 03, 2001 - 06:39 am: Edit

I'd take all mileage figures with a grain of salt, folks. Too many variables, too many possibilities for error. Some things that actually can change mpg beyond condition of engine and modifications --lead foot, amount of braking, aggressiveness of tread, tire inflation, avg speed, avg daily temperature, gas station additives like mtbe or ethanol, A/C, time idling (at 0 mpg), hills and twisting of route, type of pavement etc. Then there are errors that creep in as suggested above with odometer...worn or non-standard size tires can also make a big difference in calculation...non-standard gearing...odometer that skips occasionally (not uncommon at all)...angle of repose when filling tank...consistency of fill...temperature on fill (gas expands when hot, thus putting less "cold equivalent" gallons in when topped off) etc. Then there's the psychologically demonstrated factor that most people will tend, consciously or subconsciously, to make estimation errors in favor of their desired outcome--eg, put in 18.13 gallons, let's call it 18 for the calculation, but with 18.87, use the exact figure instead of rounding up to 19. Most results I've heard over the past few years are about the same as what I get with my 2 Discos ('94 and '95) 13.5 mpg town 17 mpg freeway, with A/C subtracting a fraction of an mpg (in winter we have mtbe in the gas, which cuts maybe an mpg). This is basically also the mileage claimed by LR. (see, for example, http://www.autofan.com/july/3/specs.htm from 1998 or http://www.cvol.net/wheels/lrover.htm for DII) Of course, tuning/mechanicals can make a big difference. Both my Discos are 3.9 distributor, and both had bad vacuum advance diaphragms when I got them. That cuts off 1-2 mpg (but interestingly increases the acceleration noticeably--simple power boost--plug the vacuum line). So...best use of mileage figures IMHO is to see what makes a difference in your own driving habits, modifications, repairs etc.

John

By dave on Tuesday, July 03, 2001 - 08:39 am: Edit

A few notes...

My Disco has larger tires and the speedo is dead on with my GPS now. It used to be close to 8-10 mph fast. 265/70-16 is current size.

Also, the only way I have ever had millage that good was for very extended trips with almost zero stopping. Any stop and go at all and the millage goes waayyy down.

By Andy Nix (Andy) on Tuesday, July 03, 2001 - 08:49 am: Edit

i'm running 245-75-16's and mine is consistant at 12.4444 or 13.2222 depending on my foot. and that's freeway driving. OME MD's, Adv rack, and stock brush bar. my RR get's 18-19 on the freeeeeeeway, and about 13 in the city ( 4.6 hse )

Andy

By jet on Tuesday, July 03, 2001 - 09:01 am: Edit

dude you all are doing great compared to me i get 250 miles to a tank and im not a lead foot

By Leslie on Tuesday, July 03, 2001 - 09:12 am: Edit

Pinned to the wall!!

No, you're right.... I'm fully aware of the discrepancy, and have not adjusted for it. Reasons being why I still throw the results out there: Usually people will post about their 14 mpg Disco here, uncorrected... so when mine says 16.5 mpg uncorrected, I'm doing okay... If someone specifies that they've corrected, then you start comparing apples to oranges. And... when my daily commuting average is 16.5, but I take a 1000 mi interstate trip and pull a 19.5 mpg average, then I'm definitely doing better on the trip than I usually get to-n-from work.

But the biggest point: When I bought this thing, I was fully aware that it wasn't a 4-cyl Honda... AND, I bought it to replace my J##p Wagoneer, which was getting 9 mpg.... AND, most importantly.. I can show the 19.5 mpg to my wife, and she'll let up on the bitching about the gas hawg. Yeah, it'd be nice if it was real, but as long as she quits griping, I'll take it and run...

I HAVE worked out the GPS calcs for my Disco, and can factor it in to get a more realistic number, I suppose, but as long as I'm usually comparing my stock Disco to other stock Discos, but even more importantly, comparing my own figures from last week to my own figures from this week, then it's irrelevant that it's not 'true, because I'm looking at the relativity.

Mi dos centavos....

By pjkbrit on Tuesday, July 03, 2001 - 09:55 am: Edit

Wow...hornets nest!!! Anyhow, my Disco's numbers seem fairly accurate. I travel the same route to our country house in the Berkshires regularly in a variety of motors. It is exactly 112 miles door to door. 112 in the Subaru, Saab 900 and in the Disco, so my odometer at least seems about right. And remember I said summer gas...winter gas up here sucks...then I'm in the mid teens, 14-16 range like the rest of you guys.
Pete

By Nathanial Bowditch on Tuesday, July 03, 2001 - 01:59 pm: Edit

Wow, lots of experts, not much common sense. The miles per gallon is an average. AVERAGE. This means it incorporates all the stopping, idling, leadfoot, braking, whatever. Idling uses a very minimal amt of fuel as there is no load, nor RPM on the plant. If your average is lower, then start looking at the the above adnauseum lists. If your average is higher, then keep it up. BTW, gasoline does expand and contract alot directly related to temp. Thats NOT a consideration for most stations as the fuel is kept below ground, where there temp remains stable around 60. It wont heat or cool that quickly between ground & car. Also the net volume remains the same, even though the gross may expand or contract in the vehicle. Angle of repose is BS also as all stations have nice level slab/pads. I am amazed at the full faith placed in satellite nav. Beware ye novice navigators. Prudent navigators never rely on one source alone. Reality is probably somewhere between the lowly odometer, and the fancy satnav.

By Blue Gill (Bluegill) on Tuesday, July 03, 2001 - 03:11 pm: Edit

are you arguing against the reality of precise and accurate 3 dimensional navigation based on real-time communication with multiple satellites? You can't get much better than that. In fact, you can't get any better than that.

You're right on with the AVERAGE point, though!

just my thoughts...

By Nate Bowditch on Wednesday, July 04, 2001 - 01:24 am: Edit

Not arguing against, rather arguing for the use of common sense. The GPS is an excellent tool, and should be used. It should not replace thinking, and awareness. Its accuracy in 2D is awesome. It does have limits. It also is not very good in 3D (unless you spend thousands). Those markers that we all pass on almost every highway mark .1, and whole miles. They are very carefully measured, and more than acurate enoughto allow the mpg calcs talked about above. Use your watch or a stop watch. It is the basis of navigation air, land sea, to not rely solely on one source of positional info. Do so at your own peril. Compare with other available info, and if the other info requires no electricity, all the better for reliabilty.
Peace, Happy Wheeling

By jcw on Wednesday, July 04, 2001 - 07:42 am: Edit

Angle of repose is NOT BS. There are plenty of stations out there with un-level slabs. And, depending on which pump, how crowded etc, you can be ON the slab with fronts, OFF with rears or vice-versa, which can make a big difference--a gallon or more, in fact. Also, different pump nozzles will shut off with different sensitivity. I always pump until it shuts off, then do one more on-cycle just to be sure it wasn't sloshing that shut it off the first time. But if you play around, fill slowly and see how much you get in the second cycle, then next time fill quickly, and see same--there can be a fair difference in that top-off amount. Point being that consistency of filling technique can also make a significant difference in top-off level.

And idling CAN be a factor, especially in winter...eg idling to warm the car up etc. Idling when the engine is cold is running a rich mixture at 0 mpg. Sure, if its only a few seconds, that's not much...but think about how big a bottle you could fill after a couple of minutes at that rate, done several times over a tankful worth of gas.

And BTW, while gasoline in the ground is undoubtedly fairly constant in temp, it will warm up quickly when mixed with hot gas already in the tank. Say you're pumping 60* gas into a half-full tank in 100* weather...it'll rapidly mix and reach a higher temperature even while filling ... and by the time you're done, that half-tank of expanded gas CAN make a noticeable difference. Remember, the pump records the metering of COLD gas, but the shut-off registers the level of much-warmed gas.

Isn't this a fun topic?

John

By ZPukajlo on Wednesday, July 04, 2001 - 03:02 pm: Edit

Well, I just came back from a four wheeling trip today. My mileage included highway and off-road. Both high and low range. The elevation factor peaked out at over 13,000 feet up. Speed varied from as low as 5 mph, tight switch backs, to as fast as 65 mph. The odometer is right on and the verdict is 20.5 mpg. It works for me and is better than my truck ever got!

By L_Tilly on Friday, July 06, 2001 - 06:31 am: Edit

As a quick side note on GPS accuracy, keep in mind that the GPS system is not ALWAYS completely accurate. They are purposfully and randomly altered by up to 5 meters, satalites signals are switched on/off for short, random periods of time, etc. This is mandated by US Govt. as a security precaution against public GPS being "used against us" (for instance in guidence systems). This is documented in the paperwork that comes with some brands of GPS...ours that runs on our laptop is one example. I cannot remember the brand, but can look it up if someone is interrested.

When I worked w/ satellite communication in the USAF we could compare our positional data off the Navy sats w/ "public" GPS. It was sometimes right on target, sometimes off by a bit. Never enough to "get lost", but enough to prevent a guided weapon from going through the White House front door and enough to potentially screw up your milage calculations.

L_Tilly lnctilly@mediaone.net
96 Disco "Beowulf" - NH, USA

By dave on Friday, July 06, 2001 - 03:04 pm: Edit

That has not been true for some time now.

As of May 2000 I think. It was called 'selective availability'...you can find a ton of info about it on the net.

By L_Tilly on Sunday, July 08, 2001 - 03:10 pm: Edit

I stand corrected. Thanks for the heads-up. I had not heard that it had been changed, but as soon as I read your message I took a quick look around the net, and there was a lot of info out there.

Naturally, I trust about 20% of what I read on the net, and about 2% of what I read in emails, until I can find a fairly reliable source to confirm. Best I found in quick checks (in case anyone else wants more info) was:
http://www.ngs.noaa.gov/FGCS/info/sans_SA/

Thanks again, and happy GPS'ing!! :-)

L_Tilly lnctilly@mediaone.net
96 Disco "Beowulf" - NH, USA

By dave on Sunday, July 08, 2001 - 04:05 pm: Edit

As far as I know dumping SA was the only decent thing that Clinton and his gang of crooks did ;-)

By L_Tilly on Monday, July 09, 2001 - 07:50 am: Edit

I'm not going to get into political opinionating here, but I will say your message put a grin on my face. ;-)

L_Tilly lnctilly@mediaone.net
96 Disco "Beowulf" - NH, USA