X300 XJR versus any SWB X308?

I have my eye on a low miles '97 X300 XJR6, and a several mid-miles 2001-2003 X308 “Sport” models with the non supercharged V8. The '97 is about 50% more money, but from what I’ve read in the “Nikasel” thread below, the X300 with the six is likely a more reliable ride over the long haul. Is that a fair assessment? Anything to watch for on the supercharged six? I’m 6’2"…most have sunroofs…will I fit? The x300 has a four speed automatic…seems like the tried and true GM unit is a safer bet than the ZF… Comments/recommendations?


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2001-2003 X308’s won’t have Nikasil problems. Even if they did, by now (in the USA and most other countries) if the engine is still sound it wouldn’t be a problem because high-sulphur fuel has been phased out (long ago.) That’s what caused Nikasil to decay.

It might have faulty timing chain tensioners though (a much more likely issue) but if those were replaced after 2003 (or the car was a 2003) it should have the latest, corrected design. Many if not most cars have had the work done by now (if they haven’t, they’ve probably gone to the scrapyard in the sky.)

The X300 XJR will probably be more bulletproof, vehicle conditions being similar, and an XJR will have more potential collector’s value. The X308 has a better front suspension design that doesn’t tramline as much as the older car did, especially with the big front tires. I don’t see a big difference betweeen the ZF and 4L80 gearboxes, the 5-speed is nice.

The X308 seems to have more annoying electronic problems though (throttle body, ABS module) that are expensive to fix if handed to a dealer or most shops to fix, but can be repaired for a fraction of the price yourself if you have some DIY skills.

Why not a 2001+ X308 XJR? In that case, the performance would be a step above the X300 to boot. It also has the bulletproof Mercedes W5A58O 5-speed transmission.


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Thanks, gents.

Dave, can the later front suspension be moved over to the earlier cars? I’m OK with do it myself. That said, the V8 XJR seems pretty complicated. On the other hand, I think they might have more accommodating seats for tall drivers…not sure about that. Also didn’t know they had a different transmission than the run of the mill XJ8. Also, a low miles XJR V8 seems to be a rare animal in black over tan/gray or black, which is what I’m after. Plenty with the white/dove interior. Lots of silver over black. Anyway, thanks again, gents.

Eric the 2 inch higher roof is on all the LONG wheelbase cars.
The back doors at 6 inches long to offset the new height.
XJR didn’t come in long wheelbase…
Put Michelins on the 97 and most of the tramming is gone.
Short list of issues.
THE 1997 …Well nothing
Short list.

Thanks, Joey. I’m leaning hard toward the '97, but they’re asking over $20K. Very low miles, but still.

I’m not clear on the transmissions in the 308 cars…is it Mercedes 5 speed for the XJR, and a sealed ZF for the rest? Reason enough to go for R. By the way, I can’t seem to find a 2001-2003 XJR in black over tan, gray, or black. Lots of white/dove interiors. Lots of silver over gray. What’s up with that?

The xjr is a modern turbo gm 400

Old but bullet proof

The 308 tranny is smooth but 100,001 mile and they implode

20 grand is waaaaaay to much for any 97 unless it’s a Gtjoey car…ha ha

Your call buy all of them

Then your set for life!

All combined were the price of a half a car new

No brainer in my opinion, I still long for my totaled ‘97 X300!! I’ve owned both and the X300 wins by a country mile.

I take it that you are comparing the Merc box to the GM40?

It’s in the GT Joey category…

Yeah, for $20K it better be the very best XJR/6 in the whole world.

I drove an XJR/6 as a daily driver for many years. Fantastic car in many respects; I really enjoyed it. Jaguar got a lot of things right. Engine and trans are very durable. I sold it at 171k miles (I bought it with 30k) and the engine an trans were still solid.

But, to be honest, it wasn’t always a pleasure cruise. Differential failure at 77k miles, wheel bearing failures, coil failures, various driveability and engine management issues, idler pulleys failing, ABS faults, multiple radio problems, seat heater failures, and a slew of other issues. To be fair, many of these things were when the car was well over 100k miles so it’s expected that more items will eventually give trouble. And, never once was I left stranded by the side of the road so, in that sense, it was very reliable.

The X300 cars enjoy a good reputation in general but age and miles will eventually take the gloss off any car. Since you’re considering a very low mileage car you might be spared some of the problems I had.

Some of the engine management electronics require specialized equipment for resetting/recalibrating the system. When I owned my XJR there was very little aftermarket/indy shop equipment available to do so, leaving no choice but to rely on expensive (and in my case, distant) dealer visits. By now I reckon many dealers no longer support the old X300 cars…but perhaps the aftermarket has caught up?



As far as I know, the later suspension cannot be retrofitted to the X300 chassis. I believe the mounting points and locations were all revised for the X308.

I don’t think the X308 XJR is significantly more complicated than the unsupercharged models. Stuff is covered up under the supercharger and intercoolers, but there’s nothing under there that seems to require regular or common service. (unlike the notorious “valley” cooling hose on the S-type R supercharger.)

Only the XJR had the Mercedes W5A transmission, and I would have to rate it above the 4L80E. Not that the 4L80E is a bad unit at all - the Mercedes unit is outstanding. At least as reliable, and probably more so than the GM unit and much more sophisticated. Even Porsche used it for their automatic 996 Turbos. It might be the only reliable item found on the Daimler-Chrysler SRT models. :slight_smile:

It may be just a current state of the market thing with so few black/black XJRs for sale. This was probably one of the more common color combos. Take a look at this list of XJRs that sold on Bring-A_Trailer and see how many are black/black…


Another question…is the interior space in the 308 better than the 300? Headroom is my big concern. (But don’t want a long wheelbase car). By the way, the '97 I’m considering is a 30K mile one owner car…appears to be flawless in photos. Thanks for the discussion. Very informative stuff.

These are the common issues with the X300:


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It’s basically the same architecture so not to my mind. Interior aesthetics are different though.


Re: Black XJRs - edited my above post to put a link to Bring-a-trailer XJRs listed with them. Didn’t watch my original post to verify the link was there. If it disappears again, it was removed!


(edit) - OK, the link got removed. I wasn’t nuts. I saw it there when I posted and now it’s gone 30 minutes or so later. Anyway of 27 XJRs (from x300 to x350, no X351s so far) 11 were black.


The 30,000 miles '97 has new Continental tires, (ugly 17" wheels to my eye), new shocks and brake pads all around, and front end bushings. New AC compressor, evaporator and hoses. Clean bottom, no leaks. A crease (not a bubble) in the headliner. Otherwise extremely well kept per the dealer (consignment sale) and photos. Garaged by original owner alll it’s life (Florida). Black on black.

The 2002 XKR V8 in the competition has 38,000 miles. Medium wear tires (Bridgestone) on nice 18" wheels. New rear view mirror. The shop who did recent inspection says it’s clean as a whistle underneath. Garage kept in Florida. A small bubble/sag at rear corner of headliner. It’s a metallic gray color with oatmeal interior. Asking ~$13K.

Both vehicles are “collector quality and rare” , and both are “in collections” per the consignment agents… I’m guessing a couple, three grand off the '97, and probably $1000-1500 off the 2002. The I6 is rated at 19 mpg, the V8 at 22 mpg.

I was surprised at the extent of recent work done on the '97 given only 30,000 miles, but that might be a plus in the long run. The 2002 might need the same any day now. Both might need a headliner.

The cost delta isn’t that big a deal for me…last car before dirt nap. I just want a "96-2002 XJR that I can drive on long trips with minimal issues.

OK…let’s vote…

Eric, You hit it on the head.
The 1997 is 22 years old, your lucky they refurbished all the bits.
You would have had to do it anyway just because of the years!
The 308 is ALOT different as everything will have to come out with the v8 cross member and all.
If your going on long rides, want a shot at diy .
The 97 is the only way. GET MICHELINS on it and you will have the best of all worlds.
Good luck either way

When my 1997 X300 was totalled it had 125+K on the clock, had never failed an MOT (annual inspection), was going like clockwork and had only had a replacement battery, tyres, rear shocks, A/C Compressor clutch, front & rear sponge isolators, coil packs, CKPS and upper on lower ones on the fan mounting.
The head lining needed doing but looked acceptable using the transparent headed spiral fixings!
All of which would be covered by the price differential if you went with the XK8 it’s a hard choice as they are both great cars however I personally would go with the X300.