This is true for CA. You can go the other way and put newer engines in older cars. But older engines in newer cars won't pass the visual check for smog and you can't get your reg tags without a current smog.

 

Older engines might not be as clean as newer engines but a 2000 4.0 uses less gas than a 2004 4.6. I guess laws sometimes don't make much sense.

 

They dont care how much fuel they use, its what comes out the tailpipe.

 

But the more fuel burnt the more pollution comes out of the tailpipe. Besides what does a 2004 have that a 2000 doesn't with regard to emission control systems. i know you didn't write the law spike don't take it personal.

 

I dont know man, it is what it is.
Yes the 4.0 and the 4.6 are the same engine and in theory they should pollute the same.
I didnt write the law, I dont get it either.
They wont let us have diesels here in the US because they pollute to much but yet they use half the fuel as a gas V8 per mile, makes no sense.
Nothing personal taken or sent, I dont under stand it either.
If you live in a state that does not do emissions testing then you are fine.
Just keep in mind that if your state starts or you move or try and sell the truck to a state that does testing you will have problems.
That being said I would drop in the 4.0 and not worry about it if I were in your shoes.

 

Doesn't matter anyway. Went to the yard today and it aint a disco, it's a friggin' freelander. But, I finally got a multi page thread going!! By the way, the province of New Brunswick wouldn't have a clue what size engine is in anyones truck.

 

All 04's had SAI iirc, and are certified as LEV. If your 4.0 ist SAI, you may need to swap the 4.6 heads onto it.

 

I disagree, a 4.0 uses the same amount of fuel, for the most part as a 4.6, 4.6 just has a little more power.

 

According to fueleconomy.gov

2000 Discovery
Fuel Type:Premium
MPG (city):12
MPG (highway):16
MPG (combined):13

2004 Discovery
Fuel Type :Premium
MPG (city):11
MPG (highway):14
MPG (combined):12

I would say 2mpg highway is more gas. The 4.0 should get you 50 miles further on a tank of gas than a 4.6

 

So I have a 2003 and have a nice little undiagnosable clatter under load, not at idle.

Anyways, I think I read I can put a 1999-2002 4.6 Range Rover engine in my 2003 right? Pretty much plug and play or are there going to be issues with ECU, Transmission, Connections?

Here is motor in question:
http://www.roverlandparts.com/1999-2...y44kmiles.aspx