I'm entering my 2003 4.2L (ZF 6speed trans) in a private car show next week and am looking for info to put on a poster. (car show at work w/80+ vehicles)

1. What is the top speed of a stock S-Type w/4.2L V8. Googled it and searched here too, I can't seem to find info on the 4.2L naturally aspirated model other than speed limited to 155mph. Does anyone know of official or magazine testing? Or.. ahem... have 1st hand experience? Hypothetically speaking of coarse ;-)
2. Any other *odd* info about the S-Type that might be musing to display on a car show poster?

 

I think you'll find 155mph is for the R models.
and 121mph is the limiter on the rest .
as the R were fitted with ZR rated tyres.
however all of the s-types will surpass there limiter in 5th gear.

 

I had my 2001 4.0 S-Type over 135MPH on a stretch of Texas highway before I decided to slow it back down to about 80MPH to avoid attracting attention from the local constabularies. I had some 'peddle' left so I did not find 'top-end'.

I'm sure the terrain and the wind might play into the equation.

good luck with the search.

 

European 4.2s were supplied on W rated tyres and were limited to 155 mph. There might be enough power to trouble the limiter but not by much.

The 3.0 manual and the 4.0 with the Ford automatic gearbox were instrument tested by the same magazine at 145 mph but on different days.

It has been suggested that the 400 hp STR would hit 180 mph if unlimited.

 

ok , so it does look the euro speck was 155mph .
but knowing the 04+ XJ8 uses the same PCM and flash files for country of origin.
and if so
it does look like the US and canadian model is different according to this link.
https://www.jaguarforums.com/forum/x...p-speed-37576/

 

When I first bought my 2006 with the naturally aspirated 4.2L I found, I think on Wikipedia, a top speed of 174 MPH, but governed to 155 MPH. The 174 made sense given a speedometer stopping at 170. I looked for that page again, but didn't see it. Wikipedia gets edited a lot.

 

Jaguar suggested that the STR would top out at 193 mph. I expect you'd need a fair length of tarmac for that.

 

That sounds too high for the drag of these cars and the power available. See https://www.jaguarforums.com/forum/s...corked-101472/ Post 7.

 

I just read that thread. They're thinking about 186 mph, so just 7 mph between what they & Jaguar reckon, with no empirical evidence on either side. I still think you'd need a looong strip to max one out.

 

Just did some calcs.. at 130mph its in 4th (1.14 trans ratio) at 5500rpm. And 5th (0.87 ratio) would be 4200rpms. So given the drag coefficient of 0.31, rear lift of 0.04, front of 0.16, and frontal area of 2.27m2.... I think a 4.2L if not limited by the computer would run 130+ w/o a problem.

 

Sure it will
The European ones are limited to 155 mph and I believe the main differences were just the tyre spec. However, unrestricted, I doubt that there is much left to go much faster either. 300 hp in a modern car that size and weight always seems to top out at around 160 mph.

 

Here is a pressure map on top. And a vector map on bottom

 

The previous owner told me he was in the country & he ran it up to 130. I didn't prompt the Q so I tend to believe what he said.
Not sure I'll ever have the legal opportunity to see what it will do. But if I ever do... I certainly will.

 

My S-type 2.7 diesel manual hit the claimed 142 mph max convincingly & that pretty much coincided with the redline in 6th. Now, they weren't exactly high geared but you're making quite a bit more power (albeit with less torque), with roughly same weight & Cd so I don't see why 145 isn't easily possible & much beyond that taking some time to get there (it is a 16 year old car). Just make sure all else is up to snuff i.e. tyres, pressures, brakes, suspension, etc.

 

Around here there is no (easy) place for me to legally see what it would do. Maybe one day..

 

​​​​​​​We're still talking about some things to put on your display board, right ;-)

 

Yep I put "Top speed = 155mph (electronically limited) "

I've owned and raced many cars over the years. Mostly drag racing or road tracks where you just can't stretch one out to its limit.

 

Having run the Nevada Silver State open road race a couple of times I'd have my doubts about 180 or 193 mph. More over, I don't think I'd try that anyway. You better have perfect brand new tires and proof of what the car does aerodynamically at such speeds. You won't survive any sort of incident should something bad happen. I had dinner the night before with a lovely couple who ran their Testarosa off the road at 180 mph and he survived somehow while she was killed. The car rolled up into a ball about the size of a card table when we drove by it. He didn't know the provenance of the tires and bought the car with 4K miles on it. I hit 160 when driving a well sorted vintage Maserati but that 1977 car was quite a handful at those speeds. Well engineered for aerodynamics modern cars are far better at those speeds. My Q45 was a dream at those speeds by comparison but it had about 320 HP and topped out at 151 even with the limiter deleted. That car had a cd of .29

It's not even possible for such speeds where I live now. I hit 100 when passing quite easily and regularly which is a problem here ...

 

Interesting Staatsof.

btw, the car show went well. I'm not allowed to post pics though because it done in a secure area. Weather was beautiful and the range of cars, bikes, projects was interesting. (we're all engineers)
I stood back and watched the Jag onlookers. (only Jag in the show). One thing I noticed they that they weren't doing at other cars was looking inside. Interior style seems to be an above avg expectation.

 

Sounds like a corporate location.

I have an engineer friend who works for Mclaren and they have similar shows involving employee's vehicles. Never seen a photo though ...