Ponder this question? 2004 Discovery 2 gets maybe 14MPG

MNinWI

Well-known member
Dec 19, 2007
74
1
I have a 2003 D2, highway at 70mph I am lucky to get 16 mph, more likely 15 mph. But slow down a few mph and the mileage gets better. Even when the limit is 70 and everybody else if going 75, I am the slow guy doing 70 mph in the right lane. On a road with a lower speed limit, my mileage gets quite a bit better.

Aerodynamics are not the strong point for the D2, you look at the back door and it is a huge area to pull a draft behind.

I do not recall my tire size, but when I replaced the tires I got ones that had a half inch taller sidewall, that geared up the vehicle about 5 percent, but the mileage stayed about the same.
 

kennith

Well-known member
Apr 22, 2004
10,409
101
North Carolina
I have a 2003 D2, highway at 70mph I am lucky to get 16 mph, more likely 15 mph. But slow down a few mph and the mileage gets better. Even when the limit is 70 and everybody else if going 75, I am the slow guy doing 70 mph in the right lane. On a road with a lower speed limit, my mileage gets quite a bit better.

Aerodynamics are not the strong point for the D2, you look at the back door and it is a huge area to pull a draft behind.

I do not recall my tire size, but when I replaced the tires I got ones that had a half inch taller sidewall, that geared up the vehicle about 5 percent, but the mileage stayed about the same.
One of the interesting aspects of the DII is it's relatively narrow mileage range between town and highway driving. There's still a gap, but not as much as one might expect. There's a sweet spot in there, but it's also pretty narrow.

A lot of stuff is playing a part in that, and it isn't particularly complicated, but it's just interesting the way that vehicle came together. The body itself does present severe issues at speeds above 90mph. Once you break 100mph, anyone can feel it. At that point and beyond, you're approaching just being at the mercy of the air itself.

I had mine to 120mph one time. I just wanted to see where the limit was; and it was indeed electronically limited. It was also drag limited. It would never have hit 121, and so far as I'm concerned, it'll never hit 120 again, either. It wasn't the worst, but I could tell very quickly that a poor decision would become very unpredictable, very quickly.

Cheers,

Kennith
 

Swedjen2

Well-known member
Sep 12, 2018
201
23
California
On the freeway, stay in the slow lane, use cruise control, keep the RPMs at 2250ish as much as practicable (about 60 mph) and get AT LEAST 17.5 MPG like I just did on a 175 mile drive. All freeway. Includes some stop and go due to Holiday traffic. YRMV.
91 octane Chevron/Exxon-Mobil/Shell.
 

ERover82

Well-known member
Nov 26, 2011
3,230
98
Darien Gap
Go compare various Land Cruisers on Fuelly. You'll see your 14mpg is right in line. Maintenance and/or removal of outside accessories can improve your mileage a bit.
 
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To compare a similar vehicle, I also have a 2001 Dakota AWD 4.7 V8 (6000lbs) which gets about 19 Imperial mpg highway, almost identical to my 1997 P38 4.6 V8. I haven't had the 2001 Disco 4.0 long enough to have a real good idea, but it seems to be 17-18, probably because it pushes a bit more wind. All in all, it seems these vehicles get pretty similar gas mileage.
 
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kennith

Well-known member
Apr 22, 2004
10,409
101
North Carolina
To compare a similar vehicle, I also have a 2001 Dakota AWD 4.7 V8 (6000lbs) which gets about 19 Imperial mpg highway, almost identical to my 1997 P38 4.6 V8. I haven't had the 2001 Disco 4.0 long enough to have a real good idea, but it seems to be 17-18, probably because it pushes a bit more wind. All in all, it seems these vehicles get pretty similar gas mileage.
Yup. Just like a G Wagon, Land Cruiser, or any other contemporary vehicle in the class with at least one solid axle, a transfer case, a ladder frame, geared AWD, and utility body.

Even modern vehicles built that way fall into the same range.

At this time, there's just no way around it beyond using a diesel engine that was/is unavailable in the US; and that doesn't count. It's apples to apples or there's no point in comparing vehicles or judging DII fuel economy, after all. A gas engine is just going to land in that range no matter what you do.

Cheers,

Kennith
 

bradartigue

Well-known member
Mar 7, 2018
110
16
Sandy Springs, Georgia
Thanks
All valid but with fuel injection and ecu mngt it isnt even close to a Mercedes 430 v8 station wagon almost the same weight.
Cant all be aero and poor Cd
The Mercedes isn't exactly stealthy
I'll put it on the analyzing machine and record the BSFC must be miserably high for an engine under 5Liters
I would argue the comparison is invalid from the very start; even on an engine stand the Land Rover would consume more fuel than the MBZ because of the very nature of how the engine and fuel system were designed.

The Land Rover has a non-integrated fuel injection system, it is literally bolted onto the old Buick/Rover V8 and made to work. Steel liner, aluminum block, pushrod, chain drive, noisy, fun, simple motor. This is a common design of the era. Regardless, the pushrod design, enormous rotating mass, dumb, reactive fuel management system, and a host of other 1990's innovations keep the MPGs low. There is no way to make the old head and valve design work more efficiently though - it is what it is, a wonderful relic.

The 430, I'm guessing is a M113, designed in 2000, a triple valve single overhead cam with cylinder bores lined in silicon and aluminum. The fuel injection system is integrated into the design of the engine, it can compensate (vs. just report or alter fuel mixture) for a broad array of anomalies during operation, etc. If it is the 5.0 it can deactivate cylinders when not needed. Although nearly impossible to service, the M113 is a reliable motor with a lot of torque.

Who wins? The Land Rover. The M113 has 16 spark plugs. We make more HP with 8 fewer spark plugs.
(also an invalid comparison)
 

bradartigue

Well-known member
Mar 7, 2018
110
16
Sandy Springs, Georgia
On the point of servicing, in itself the M113 is not difficult to work on. I should be specific, it was jammed into engine bays to the extent of being difficult to get to certain parts easily. It does benefit from being very reliable, so maybe the design intent was met.

As to the other comment I would agree the M113 would get nearly as bad mileage when attached to the Discovery driveline - but it should get somewhat better all around as the idle time efficiency would be much better. The efficiency of the design of the head and fuel management also play a part, but still, the range would be in the shitty zone, likely not much better than the end point of the Discovery plus a few (17 MPG - 20 MPG).