I bought a 2003 3.0L for the cheaper price of entry. Earlier this year, it cost me $10,000 even. I suspect that the 3.0L might be slightly more reliable, but an 04 or 05 should be more reliable still regardless of engine. I also chose the 3.0L for its slightly better mileage, although for some that is a debatable point. They are probably the same....

Another reason for choosing the 3.0L is that its lower HP and torque won't strain the automatic transmission as much. The V6 and V8 models have the same transmission.

Until 1998, Jaguars came with 6 cylinder engines only, so I opted for tradition!

To be honest, I would have chosen the V8 if I could have gotten it for the same money, knowing what I know now.

 

I don't own an S-Type so I cant speak from experience, but from what I hear the '05-newer models seem to be more reliable than the '03-'04 models, yet the '03-'04 models are still fairly reliable. If I were buying, I'd opt for the '05.

As far as engines, V8s are a lot of fun but FloridaJag has a great point in that a V6 wont strain the tranny as much. As far as fuel effiiciency, I was under the impression that the V8 was better. I know it's slightly (only slightly) better than the 3.0 engine on the X-Type but that could be due to the 5 speed transmission as opposed to the S-Type's 6 speed.

 

05 is updated exterior, a lot higher price on non Rs then 04

 

Simply put, get a 2005 or newer, and the 3.0 is both easier and cheaper to maintain. If you want a highway cruiser, the 3.0 is your pick. If you want more of a racer and are willing to spend more time and money to fix it, go with the 4.2....

I bought the 3.0 with about seven months of factory warranty remaining on it. I had the dealer do about $3,000 worth of warranty work to it before our warranty ran out two weeks ago. Rather than purchase an extended warranty, I decided just to earmark a couple grand in a money market account as my S-Type Repair Fund....

 

I would recommend going with a 2005 or later. Try to get a Certified Jaguar with the extended warranty. I have a 3.0 V6 and that is plenty fast enough for me. Also, the V6s are more plentiful so you can find one easier and are more likely to get a better deal.

Mike

 

I've owned 2 Jags with V6's - the 2.5 and the 3.0 in X-Types. I now own an 06 S-Type VDP with the 4.2. The performance of the 3.0 in the X-Type was pretty good, but, the S-Type I have now is substantially quicker. Fuel economy wise, The S-Type, on trips, is doing about 4 - 5 MPG better than my 3.0 X-Type did. I can't advise you much on maintenance cost - other than my oil changes cost me about the same as my X-Type did. My S was a CPO car - I bought it with 48K miles on it, and its under warranty until late 2011. The dealer offered me the option to extend it a year beyond that, but, wanted $3K to do it. I decided to pass on that. Whichever engine you decide to go with - get a CPO car from a JAG dealer with the factory backed warranty it carries to 6 years/100K miles from its original in-service date.

Regards:
Oldengineer

 

I have an 05, 3.0v6. If the mileage is a concern, go with the V8. It works a lot less to move the car therefore gets better mileage. This comes from back to back drives. As far as reliability goes, the 3.0 is a Ford engine and the 4.2 is a Jag. From what I can gather either motor is fairly strong. If I had it to do over again it would have been the 4.2.

 

Josworth: Having owned the 2.5 and 3.0 versions of the V6 - They're derived from the Ford Duratec, but, made much more power. Jag thoroughly re-engineered them - the engine internals are different, heads are different, they're high compression, the induction system is much more sophisticated, etc. The Jag 3.0 compares very well with the normally aspirated BMW 3 liter engines of the same period.

Regards:
Oldengineer

 

Oldengineer - were you referring to the engines in the S-Type or in the X-Type? If you meant the S-Type, do you know what the equivalent size engines are in the X-Type (Ford or Jag-modified, essentially)?

 

Oldengineer: Yes, the 3.0 is different in the Jag but I would debate the engineering. It was my understanding that the 3.0's development was Ford's while the V8 was Jag's. This was part of the shared development of the LS/S Type. The V6's are part of a large family of engines that are built in Cleveland, Ohio. This includes versions used in many Ford, Mazda, and Jaguar cars. Until just recently, Mazda and Jaguar were the only ones to get the V6 with variable valve timing. Here is the best excerpt from an article I could find with just a short search.

"The 3.0 L Duratec 30 or Mazda AJ was introduced in 1996 as a replacement for the 3.8 L (~232 cu in) Essex V6 in the up-market versions of the Ford Taurus/Mercury Sable. It has 2967 cc (181 cu in) of displacement and produces between 200 hp (150 kW) and 240 hp (180 kW). The same basic engine is used in the Jaguar S-Type, Lincoln LS, Mazda MPV, Mazda 6, Mondeo ST220 and many other Ford vehicles. It is essentially a bored-out (to 89 mm) Duratec 25 and is built in Ford Motor Company's Cleveland Engine #2 plant in Cleveland, Ohio. A slightly modified version for the Ford Five Hundred entered production at the Cleveland #1 plant in 2004.

There are two key versions of the Duratec 30:

DAMB - The Lincoln LS and Jaguar AJ30 versions have direct-acting mechanical bucket (DAMB) tappets. Output is 232 hp (173 kW) at 6750 rpm with 220 lb·ft (298 N·m) of torque at 4500 rpm.
RFF - The Taurus/Sable/Escape version uses roller finger followers (RFF) instead and produces 201 hp (150 kW) at 5900 rpm with 207 lb·ft (281 N·m) of torque at 4400 rpm.
The 2006 Ford Fusion, Mercury Milan, and Lincoln Zephyr feature a version of the Duratec 30 using variable valve timing. The engine has an output of 221 hp (165 kW) at 6250 rpm, and 205 lb·ft (278 N·m) of torque at 4800 rpm.

The 2009 Ford Escape and the new 2010 Ford Fusion feature a version of the Duratec with engine output now at 240 hp (180 kW) at 6550 rpm, and 233 lb·ft (316 N·m) of torque at 4300 rpm.

A Twin-turbocharged version of this engine is used in the Noble M400, a British supercar. The engine is rebuilt and tuned to a max power of 425 bhp (317 kW) at 6500 rpm, with a torque figure of 390 lb·ft (529 N·m) at 5000 rpm. Noble has used forged pistons, an oil cooler, a larger baffled oil sump and extra cooling ducts to maintain its durability.

Mazda's MZI version adds variable valve timing, as does Jaguar's AJ30. Note that the MZI name is also used in Europe on Mazda's version of the Ford Sigma I4. The 3.0 L, 226 hp (169 kW) V6 used in the Mondeo ST220 is called Duratec ST. The 3.0 L 204 hp (152 kW) V6 in the Mondeo Titanium is called Duratec SE."

 

Not to step on anyone's toes.... The X and S use the same V6 motors. There are actually three gasoline versions of the V6. There is the AJ20 that is a 2.1 liter(but marketed as a 2.0 liter), the AJ25 that is a 2.5 liter, and the AJ30 that is a 3.0 liter. The AJ20 is the base UK gas engine in the X. The AJ25 was also in the X and the base engine in the US. The AJ25 was also the base engine for the S in the UK. The AJ30 was/is the optional engine in the X, the base engine in the S for the US, and the base engine in the XF in the UK.

 

The 3.0 used in the X-Type is essentially the same as the S-Type's engine. The 3.0 in the X is rated at 227 HP, and, I think 236 HP in the S. The difference is because the engine is mounted sideways in the X, and, its exhaust system is more restrictive. The S Type 3.0 gets better fuel economy because its not AWD, and, it has a 6 speed tranny with a decent overdrive. Anyway, the 3.0 used in both models is the "AJ" series V6.

Regards:
Oldengineer

 

Thanks everyone!