I know it is over 4000 pounds but I thought it would still be faster. My 2004 350Z does 0-60 in 5.6 seconds and it is the roadster which is 200 pounds heavier than the hatchback. And it only has 287 HP. If I get a XJR it would be a 95-97 because of how dependable they are. I saw later XJR's are very fast but the parts to repair them are $$$$$ and they are less dependable than the X300's.

 

Back in 1997 a brand new Jaguar XJR would set you back something to the tune of 70 grand, more or less. That's over 100K today, adjusted for inflation. I am guessing that the Jaguar design team has correctly assumed that most people who shell out that kind of cash for a heavy luxury sedan are not terribly interested in stoplight races. Consequently, they tuned and geared the car for smoothness and reasonable fuel economy. I would venture to guess that 0-60 times in the 5-6 second range were never a design goal. It's probably not all that difficult to improve the 0-60 by changing the gearing, while sacrificing a bit of top speed and fuel economy. It seems to me that most XJR owners are not interested in this kind of modification.

 

When the XJR/6 was designed and marketed a 6.6 second 0-60 time was very competitive for that type of car. But, yeah, by *modern* standards, it is very ho-hum. Ordinary Toyota/Nissan/Honda family sedans are quicker!

Cheers
DD

 

Not really, IMHO

The car was under-marketed. Jaguar wanted to capture, I think, the imagination of some BMW owners. I don't think their heart was fully into it, though. I think it was a bit of a market experiment after going way too long without a true performance-oriented model in the catalog. They were remembering a time when "Jaguar" and "performance' went hand-in-hand....but perhaps were not sure how the market would react

However.....

If you look at the XJR/6 marketing/advertising that DID exist, Jaguar was very quick to emphasize the 0-60 times and the top speed, along with the other performance-oriented features. The car was featured as having a slightly ominous aura.

Along those lines, the 3.27 gearing was specifically used with just *one* goal in mined: to allow the manual transmission variants to reach 60 mph with just one shift and thus keep the 0-60 time just under 6 seconds.

Stoplight races may not have been the actual design intent but, at the same time, they were not too far out of the minds of Jaguar when they built and marketed the car

Cheers
DD

 

Steve W quote "If I get a XJR it would be a 95-97 because of how dependable they are. I saw later XJR's are very fast but the parts to repair them are $$$$$ and they are less dependable than the X300's."

Where do you get your data to make that statement about reliabilty?

All studies that I have read , about the XJ series, certainly do not back that up.

 

What studies?

It is certainly my impression from reading this forum
for a number of years that the X300 is the pinnacle
of drivetrain reliablility in the Jaguar sedan series.

 

A year ago I read two different Jaguar XJ series overall reliability reports/studies. Which of course I cannot find now.

They rated the XJ series 2003 to 2009. In these studies the XJ series during this period were superior overall compared to the other Jaguar models and the XJ series from 2006 to 2009 were rated the best from an overall reliability point of view.

Oh and one study made a point of saying that from 2003/4 reliability for Jaguar overall had greatly improved.

One study was UK based the other was a motoring organisation in the US.

I certainly would not base my impressions solely on any forum for any car.

 

While interesting, unfortunately the inferred question was which was more reliable, the X300 (1995-1997 North America) and X308 (1998-2003 North America).

So the studies noted in your reply only covered the X308 to X358, not the X300 and thus didn't compare the X300 and X308.


I think if you were to ask anyone that has owned an X300 and X308 for any length of time, which includes many on this forum (of course!), while they may favor one or the other series for any number of personal preferences, they will as a majority agree that the drive-train (specifically) of the X300 is generally more reliable and trouble-free as a whole than the X308.

X300:

The AJ16 engine has no real systemic issues, except for the upper cam chain tensioner piston, which is isn't catastrophic (more of a noisy nuisance) and is generally successfully addressed with the uprated part.

For the NA X300 cars, I've not heard of any significant issues with the ZF 4HP-2x transmissions.

And for the X300 XJR and XJ12, the GM 4L80E, which is a direct descendant of the TH400, while not a market leader in sophistication, is considered one of the best and most reliable automatic transmissions ever made.


X308:

However the AJ26 X308 V8 engines had a number of not insignificant issues such as water pump, thermostat housing and serious catastrophic cam chain tensioner failures that weren't addressed until 2002/2003.

And for the NA (non-XJR) X308, the ZF "maintenance free" transmissions are well known to require a rebuild for A drum failures as they approach around 100k miles, sometimes sooner. To be fair, the Mercedes transmission on the X308 XJR is supposed to be very reliable.


Or course of these X308 issues can be managed and even proactively addressed (or attempted to be addressed with the ZF transmission) but the X300 as a series doesn't suffer these same types of issues out of the box. So in my estimation that makes the X300 the better drive-train as far as OEM reliability as these types of issues don't have to be managed at all.

...now if we get into a discussion about engine performance, benefits of more gears, gear ratios, styling... that is a different measure and conversation, much of which is subjective and that's OK

So I'm not saying the X300 overall is better than the X308, just addressing the comment about drive-train reliability and the "study" cited.


There is a reason they say the AJ16 is "bulletproof"


.

 

I think you received a lot of good replies to the "why" portion of your post about X300 XJR (XJR6) performance.... and as they all said, it really has to be put into the context of the early 1990s when this car was developed.

And in that context one can compare the XJR6 326 bhp (243 kW; 331 PS) and 378 lb·ft (512 N·m) engine specifications.

For example, the 1996 Chevrolet Corvette GS came with the high-performance LT4 5.7l V8 engine, producing 330 hp (246 kW) and 340 lb·ft (461 N·m) of torque. Not that the Corvette was the pinnacle of performance in 1996, but that puts it in perspective.

A 1994-1999 Ferrari F355 made 375 hp (280 kW) and 363 N·m (268 lb·ft) with its 3.5l V8.

And the M5 version of the BMW E34 was produced from 1988 to 1995. It featured an S38 straight-6 engine, originally a 3.6 L with an output of 232 kW (315 PS; 311 hp), later upgraded to a 3.8 L producing 250 kW (340 PS; 335 hp).

My 5.7l LT1 V8 equipped 1995 Buick Roadmaster made 260 hp, and my 1995 Buick Riviera with its Eaton M62 supercharged 3.8l V6 made 225 hp. In 1996 the Riviera upgraded the supercharger to the same M90 we have on the XJR6 and bumped the hp to 245.


So with that all in mind, the XJR6 was in good company and for a short time was the fastest production sedan in the world... although the BMW E39 M5 soon took that title in 1998



But it all boils down to what you are looking for, what your goals are and if you can be happy with the reality of what the car was and can be.

I'll be the first to admit I like to tinker, and would love to play with a larger SC pulley, better intercooler bits, a different differential ratio, etc... and maybe I will one day, or maybe I won't. But while any of those options may add a bit more performance, the truth is that unless one spends thousands and essentially changes the entire character of the car, you still can't hope to approach the performance of modern run-of-the-mill cars, much less modern performance cars.

But I'm OK with that, as the XJR6 is still a high performance sedan and again in the context of its time is pretty impressive.

I'm happy to accept the car for what is fundamentally, make a few minor improvements, but appreciate it for what it is. Once one realizes that perspective, the urge to try to make the car something it isn't just floats away


.

 

I had read on here and elsewhere online about air suspension problems and how expensive the parts to fix them were. I think it was the generation right after the X300. It also looked Kirk all XJR's after X300's had air suspensions which spooks me. I like the simpler is better philosophy. If I get an XJR I can't afford 20K so I would not have tons of options of years to choose. Thanks for all the input given. It's nice to hear about the history of the development of the XJR.

 

Nope, air suspension started in 2004 with the aluminum-bodied X350s; the X308s after the X300s had V8s and 5-speed automatics that are not quite as simple and bulletproof as the X300s' straight-6s and 4-speed automatics, but are still reliable if the fluids are changed regularly. Generally speaking, the X308s are somewhat more complicated so there's more to break, but they run a close 2nd in terms of reliability to the X300s. For $20k, you can get a last-of-the-line 2003 X308 and still have plenty of money left over in reserve for servicing.

 

And the XJ6/R has a nicer dash layout

 

Is it worth mentioning that the X350 looks terrible compared to the X300/ X308, and that at least to my eyes, the X300 interior and exterior detailing is superior to the X308?
As for the performance, the fact that the 0-60 time was competitive at the time has been established above, but let's not forget the punch it has when it is rolling. It has been said before, but it just keeps on going until you run out of road or nerve. It was astonishing when new, and none too shabby to this day. I owned my current car when it was new, and bought it to replace a BMW 535, which lets just say I didn't under drive. The difference was breathtaking, and friends still recollect their first experience in the XJR ( some still break into a cold sweat at the sight of it!) Yes, there are many more cars on the road today which are faster than it than there were in 1996, but it is still a small minority of road users that can put the wood to an XJR. Oh, and it still only costs about the price of an alloy wheel upgrade for the "competition"
And try wafting along as smoothly on British roads in an Audi or a BMW........

 

I drive my XJR daily. It goes like a rocket, I can blow most other cars off the road. Yes a 500 bhp Ferrari/Porsche/modern XJR/WRX etc can beat it. But there aren't many around my corner of the world, and they aren't a whole lot quicker.
Over 300-350 bhp it starts to get incremental, and you've really got to hammer a more powerful car to comprehensively beat an old XJR

 

Interesting info here !!! I can only confirm all this. I have myself a little collection ...
94 XJS Conv 6.0L V12 black/tan
95 XJS Conv AJ16 racing green/tan
95 XJR racing green/tan
97 XJR black/black
The last one is my daily driver and they are all great cars to drive.
A real Jag enthusiast.
marmar1305

 

I have had a few Xj6,s in my time and the x300 is the pinical of them all. It is the tidiest XJ6 of them all in design and the most dependable considering it is quite a much more modern car than the earlier XJ 6.s I consider this car one of the most beautiful cars ever made. Its not handsome, good looking or even masculine, its simply artistically beautiful. Finally I would like to say to all the readers here debating this car that there is a well known saying about Jaguars, and that is: "You either love them or you hate them" and after many years of studying beautiful cars and real traditional luxurious interiors of such cars, that saying probably came from the other more common saying , which is: " You either get it or you don't "

 

My XJR is still relatively new to me, it's an auto gearbox. Despite knowing it's a big old bus, I wasn't immediatly impressed with it's throttle response or speed off-the-mark. Other than general maintenance, my only performance mod so for is swapping the crank sensor bracket for one from XJRengineer, on this forum, to give it a little more ignition advance. Logging the data using "RaceChrono" GPS app on my phone for a before & after on the same section of road, on the same day, same weather, about 1 hour apart I had a before 0-60mph time of 6.3 secs and an after of 5.9 secs. I did a couple of runs for both before & after which correlated. This may not be a wholly accurate time, but I used the same logging for both, so should at least give a relative indication. I think there is more to come easily, reading on here others experiences with swapping diff ratios & crank pulleys, but I can't comment personally. The interesting thing I've found, is it is a comfortable easy cruiser, but it has some go, when you've had enough of cruising along.

 

Depends on the sample rate of the GPS as it's not required to be very fast or accurate . It cranks out a number and says there you go your good , not .

 

Yep, agree. Away from the numbers, the throttle response was definitely noticeably improved.

 

My car is manual. The previous owner, who is often on these forums, told me he had done 0-60 in 5 secs at Manfeild race track.
I don’t like giving the manual drivetrain hell away from the mark in first gear, so I tend to use 1st to get smoothly rolling, then go into second quite early, then give it some gas. So my 0-60 would be fairly poor compared to an auto.
But my 50-75 (80-120km/h) in 3rd gear is about 4 seconds, which is where all the fun is for me.
I keep feeling tempted to change my diff ratio from 3.27 to 3.58, but that will take $$ and I like the relaxed gearing on the open road - 100km/h is about 2000-2100 rpm.

I have ordered a Kiwi-3 OBDII device which should arrive soon. This is not a patriotic purchase (!) as it is from a US company - I don’t know why they called it Kiwi... it will be interesting to see if this gives acceleration times. If so I will post. I never found the free Dynolicious app worked that well for me - big time lags, and the cellphone kept moving which stuffed up the readings.

I want to use the Kiwi-3 to see what my maximum MAF readings are with my current set up before I consider further expense such as supercharger porting, smaller pulleys, etc. I already have a Powerhouse 10% bigger crank pulley, which really does make a difference, and Andy’s reprogrammed EPROMs, hence no Andy-bracket as well. I am thinking about custom extractors but still need to go see the guy who could make them.

I had a freer-flowing exhaust made last week, but it’s quite loud under full throttle. I went to see my mechanic today to see if he thought it too loud in a ‘drive-by’ test - he thought it sounded great. I don’t want to be one of those guys that wakes up all the neighbours... it has two large bore long pipes that merge into a common 2-in, 2-out muffler way back , mimicking the TT-exhaust concept of AJ6 Engineering, and I think low and mid range torque is better...

The Venom cooler from Steigermeier seems like a worthwhile mod to reduce supercharger heat. Seriously thinking about this, and I have a spare Eaton M90 which would make it an easy job to do.