| Author | Message | ||
     Alan Yim (Alan) Senior Member Username: Alan Post Number: 389 Registered: 09-2002 |
The new Discos have a 4.6L engine that results in approximately 15/20 mpg, city to highway respectively (as per LR stats). If you were to put that same engine into a D1, would fuel mileage be better because assuming the D1s weigh less, the engine isn't working as hard. I know there are limits to this question where it will break down but the 4.0L and the 4.6L engines are not drastically different in displacements, hence my question. | ||
| Ron Brown (Ron) Member Username: Ron Post Number: 75 Registered: 04-2001 |
Between 02 and 03 DIIs lost 1mpg Ron | ||
| Dean Chrismon (Chrismonda) Member Username: Chrismonda Post Number: 59 Registered: 12-2002 |
My brother has a 2002 Chevy Silvarado Z-71 short bed that weighs a hell of alot less then my D1. It has a 327 5.3 and it gets around 14 on the highway. Don't bitch his truck only carries two people. Considering the weight of the LR I think that the engine does pretty good for mpg. | ||
| Alan Yim (Alan) Senior Member Username: Alan Post Number: 391 Registered: 09-2002 |
I've come to accept the mpg thing a long time ago but was just wondering when I was told the 4.6L fit in the D1s relatively well. My old Pathfinder did 16/21 mpg but when I locked the diff, I saw numbers as low as 10 so my Disco doesn't look that bad. I know that after a certain point, the bigger the engine, the less fuel efficient it is but in this case, the two engines aren't really significantly different so thought maybe the amount of weight the engine has to push around may have a bearing. | ||
| J E Robison Service Co (Robisonservice) Senior Member Username: Robisonservice Post Number: 24 Registered: 10-2002 |
The 2003 gets slightly better mileage than the D! due to more sophisticated engine management, not a bigger engine. If you install a 4.6 in the D1 and use the GEMs electronics your mileage will go down a bit. Futhermore, you can't install a 2002 Bosch 4.6 block in a GEMS truck without welding because the Bosch block has no provision for crank sensors and the crank end is different. This engine WILL fit with minimal work into older 14CUX trucks, though. | ||
| Alan Yim (Alan) Senior Member Username: Alan Post Number: 392 Registered: 09-2002 |
My assumption is that the truck would be rechipped as well to account for the newer engine. Thanks for the responses though. | ||
| J E Robison Service Co (Robisonservice) Senior Member Username: Robisonservice Post Number: 30 Registered: 10-2002 |
I think you are confusing rechipping with a completely different engine management system. The Bosch 4.6, for example, has a redesigned intake system that contributed to the efficiency improvement. You can't use that in a GEMS truck unless you change all the front end wiring to Bosch - a huge job Rechipping a GEMS ECU and installing a 4.6 motor is not going to improve mileage but it will improve power. Furthermore, all the chip conversions I've ever seen program the engine for max power instead of programming for minimum emissions as stock. | ||
| Alan Yim (Alan) Senior Member Username: Alan Post Number: 393 Registered: 09-2002 |
Ahhh...ok, thanks. | ||
| Norm Orschnorschki (Norm) New Member Username: Norm Post Number: 12 Registered: 02-2003 |
In my '95 I found that the 4.6 got the same (if not better) gas mileage than the 3.9B, with A LOT more power. In my opinion, the 3.9 is an adequate (just barely) power plant, that has to be flogged hard to carry so much weight up hills, etc., which would explain the crappy gas mileage. The 4.6, while not a brute, is more than adequate in a Disco with no decrease in gas mileage. | ||
| Alan Yim (Alan) Senior Member Username: Alan Post Number: 395 Registered: 09-2002 |
What was the cost to change engines? | ||
| Norm Orschnorschki (Norm) New Member Username: Norm Post Number: 13 Registered: 02-2003 |
Well, this was a couple of years ago and it was not cheap, but since I had a blown 3.9B and an otherwise perfect '95 with only 40K miles, it was worth it. But to get an RPi 4.6 long block w/ Tornado chip, new front cover/oil pump and water pump with a 12/12 warranty installed cost me about the same as what the dealers charge to put in one of their 3.9s, which is just as likely as not to be a rebuilt motor. It was the best thing I could have done under the circumstances, although I probably wouldn't have done it if I didn't have the original motor fried. Knowing what I know now, I could have done it for a lot cheaper , especially without the warranty, since there are many more sources for 4.6s these days at competetive rates. ---Norm | ||
| OLIVER CLOTHSOFF (Everythingleaks) Senior Member Username: Everythingleaks Post Number: 235 Registered: 10-2002 |
It is the same crank sensor between the GEMS system and the BOSCH system. This is the only lucas part left in the engine managment system of the DII and 4.0/4.6 RR 99-02. A bosch short block and a GEMS short block are identical other than the cam gear. The bosch system uses a different pattern. A 14CUX truck has no crank sensor because it has a distributor and is only OBDI so it doesn't require a misfire monitor. | ||
| Jeffrey L. Price (Jlprice) New Member Username: Jlprice Post Number: 3 Registered: 02-2003 |
There was a GEMS 4.6 in one or two years of Disco and 38A Range Rovers. I saw the break down of engines to model years in a recent Land Rover Enthusiast mag. That swap should be not bad at all. I have been kind off watching the junkyard web pages on the prowl for one myself. It is hard to make a linear comparison between displacement and fuel economy. I had a buddy that had an Isuzu Amigo with a staright four that got 18 to 20, which is the exact same mileage I got in the old 3.5l Range Rover. A slighter larger engine requires less throttle for the same amount of work so it could actually do better than the smaller engine. On the other hand with all that torque it seems a shame not to get into the pedal once and a while.  -jeff |
