[Alan Lindsay]

Hi all,
In good condition is there substantial performance difference between the 4.0 RR engine 4.6 lt?
Al

 

[95classiclwb]

simple answer is yes, there is a difference between 4.0 and 4.6

 

[Escape]

Yes, the 4.6 has about 15% more power and torque.

Whether you'll notice it, will depend on your driving. A 4.0 (in good shape) will do perfectly fine under normal conditions. But if you want to use all there is, a similar 4.6 will always have more to offer.

 

[scimitargtc]

Had a 4.0 litre ok swapp d to a 4.6 and definitely noticed improved performance given that both cars were n Xs of 100k miles not km

 

[Richard_G]

The later Thor, in both engine sizes, produces more power than the GEMS too. Better lower down due to the longer intake tracts.

 

[xrav22]

Even better the 4.6 transmission is much better.

 

[Gordo51]

There was a noticeable improvement in performance going from my 98 4.0 GEMS to my 2000 4.6 Bosch. The 2000 is actually quite pleasant to drive.

 

[Escape]

The later Thor, in both engine sizes, produces more power than the GEMS too. Better lower down due to the longer intake tracts.

Actually, the later Thor engines are marginally down on top end power. They do have more torque at a lower rpm, so the powerband is better usable, especially in a heavy car like a Rangie.

 

[DFNDTHIS]

The 4.0 in my '98 GEMS slipped a liner at 180k and I replaced it with a 4.6 The performance improvement was fantastic. Not sure how much better the 4.6 transmission is, but the original tranny in my truck is doing just fine at 250,00 miles and is working much less with the 4.6 pushing it. Drastically fewer downshifts and just overall smoother performance.

 

[Eric Lording]

I had a 4 lire 2001 P38 with the improved airflow head (by BMW). I replaced the 4.0 with a 4.6. Correct cam and all, but I did not have the early GEMS EFI so could not tell the ECU that it was a 4.6. It did go harder, but it was only when thrashing it. The 4.0 Auto was able to handle the extra power just fine. All in all I would not recommend spending the money. Maybe a rechip by the mob in QLD ''Roo Systems'' would return the same improvement in power and a bit more maybe.
All in all, It was a lot of work for little return and it did burn more fuel.

 

[Reinhoud]

The 4HP22ZF gearboxes, like in the 4 liter are able to handle up to 380Nm, that's what a stock high CR 4.6 cranks out, so it shouldn't be a problem, only when you start modifying the 4.6 it might become a challenge