55 on a 2 lane going up north. on HWY 29 (4 lanes) i usually go around 75 and get 17 mpg. without a boat i would get probably 16-18 (but i seldom leave our boat at our lake home).

even 30 cents, its still worth it, you know it will be more reliable, and you know the person you sell the truck to isn't getting screwed.

 

I did the math and found that I was actually saving money by running at least 92 octane. I get more mpg than the equivelant price amount of the regular (so if I put $25 in premium and $25 in regular I would get more milage out of the premium). Also most countries other than the U.S. use higher octanes. I know that 87 is hard to come byin costa rica (I believe they only have two grades at most gas stations with nothing lower than 90ish) and I would imagine the closer you get to venezuela, the better the gas gets. Someone correct me if I am wrong...

 

Disco Dave, you are absolutely right, it all depends on how you drive it. In extremely cold weather consumption is higher. LA freeways at rush hour have the same impact. At 65, the Disco gets much better mileage than at 80+.

Unfortunately, the DI & DII have not been endowed with great aerodynamics, so the higher the speed the worse the consumption.

By the way, the 2000 SD in discussion has 80 K Miles, its original o2 sensors (all 4), its original spark plug wires and it passes NC state emissions (similar to California) inspection with flying colors every year.

 

the aerodymanics are HORRIBLE!! my wind deflector on my roof rack only stops the wind noise, no hope of improving the aerodynamics with that thing! but i know i didn't buy this truck for the aerodynamics or the mpg. i kinda like the fact that its cool and slow...less speeding tickets that way!!

 

Disco Dave, I love the shape of the D1 and D2 and the off road capabilities, it is the reason why I own the three. For gas mileage, I would use a Saab 95 Aero, even my M5 gets 27 MPG on the interstate.

I learned to drive in a beat up old series II with the three levers on the transmission tunnel.

 

AMEN!! they are awesome trucks...i think i will always have at least one. do you really have a unimog? i'd love to get one of those, then my buddy with the Pinzguar and I can really have some fun!

 

A 67 404 with 2.2 L gas, offset axles with reduction gears in the hubs, 6 spd forward, 2 speed reverse. It is not the one in the picture, it is rusty and old. We use Unimogs overseas as farm implements, they are working trucks. Farmers use them like they use a john deere on a small farm here. The word stands for UNIversal MOtor Gerat. Gerat in german means device or tool.

 

I run either Sunoco or Shell v-power, both 93 octane. The previous owner always used regular unleaded. I used to run reg when I first got it only because it didn't say "premium unleaded only" inside the fuel door (like a Jag or Benz) which would explain why I was only getting 7-10mpg. Also, I found out the hard way on my Benz that running regular will destroy the catalytic converter. So now I get 14mpg around town using 93 octane.... the extra $$$ to fill up pays for itself.

Eric

 

The 3.9, 4.0 and 4.6 are the same engine just different strokes.
Non of these engines use a EGR (exhaust gas recirculation) valve.
The EGR has two main purposes, one is to reduce combustion temps and the other is to reduce emissions by buring some of the exhaust gases in the combustion chambers.
With no EGR you need to run premium gas to keep from baking the motor oil inside the cylinder heads and valley pan.
When you bake the oil inside the engine you are creating sludge which will kill your engine.
So you save a few bucks now but you spend four times as much later.
As for other countries, they dont have 3 grades of gas, they have 2, 95 octane and 110 octane.
There are more diesels on the road in other countries than gas cars. Only in America do diesels get a bad rap.
Bottom line is this, LR knows what they were doing in requiring premium gas.
If it was not required then they would say that it is "recommended but not required", but they dont, they say that it is required.
If you want to be cheap, drop HBO.

 

Spike555, you make a great point in regards to the lack of EGR on these engines, to keep combustion chambers cooler at light open throttle and lean conditions. EGR never comes on at idle or at wide open throttle, it does at cruising speed.

On the other hand, these engines use knock sensors to listen to pre-ignition or detonation in the combustion chambers so that the ECU can manage timing and injection.

So, when I get a free weekend, I will do the 60 K Mi service on the 2004 4.6 L, despite the fact that it has 48 K Mi. Will replace all the fluids with their synthetic equivalent from Mobil 1 and will start it on a premium unleaded diet.

Will report back in 5000 miles the average MPG, using premium in the 2004.

Someone made mention in an earlier response to the DRIVE AROUND THE WORLD LONGITUDE EXPEDITION: http://www.drivearoundtheworld.com/vehicles/

I wish I knew what type of fuel did they use going though central asia.

My favorite clip about the disco II:
http://www.drivearoundtheworld.com/m...-LONGITUDE.wmv