The V8. has 8 plug leads (wires), the 6 has (you guessed it), 6 !!!!......Roger.

 

Macman, with todays modern engines, they have hidden a lot of the top of the engine with fancy covers and whatnot. In a lot of cases, these covers will sometimes say V6 or V8 on them. In some cases they will even advertise this on the side of the car. But, ultimately, the test that I would tell you to use is to look on the side of the engine where the exhaust leaves the engine. Count the tubes on each side of the engine. You can run into a few different combinations this way:

4 tubes on 1 side, none on the other (inline 4)
6 tubes on 1 side, none on the other (inline 6)
3 tubes on each side (V6)
4 tubes on each side (V8)

With this being said, you may find some oddities out there like the motors in the Chevy Colorado (5 tubes on 1 side for an inline 5) and the Geo Metro (3 tubes on 1 side for an inline 3). These are just 2 examples of the strange things that you can find. But, 99% of the engines you are going to run into are going to fall into the first 4. Keep in mind that the tubes may only be but a few inches long. So, look right up against the engine.

If you remove the engine cover, you can normally get a fairly good idea by also counting the number of tubes on the top of the engine for the intake. This is fairly good for modern day cars, but the older cars the tubes simply didn't exist or were not very pronounced.

 

Why complicate this ? A V8 has 8 spark plugs, a V6 has 6. Your XF is a 5 litre V8........Roger.

 

But just to mess with some of us, some of those German machines, and Chryslers have 12 sparkplugs in their V6's. (Slk230/Crossfires) Damn nuisance to change too.

 

Jaguar only export the V8s to the US. The V6 turbodiesel is Europe and rest-of-world only, and the V6 petrol is only special order now, I believe again, not USA.

Petrol is so cheap in the US, nobody seems to be bothered by the V8 fuel consumption figures. Here in the UK at least, it is now a diesel market for large cars, as petrol is £6 = $9.60 a UK gallon. It doesnt take long to rack up big savings when your diesel car does 40+ to the gallon !

 

Yup, Aston Martin had one and I believe the Lister 3.8 litre Jaguar also but this is a 2010 XF......Roger.

 

It took me almost 5 hours to change all 16 plugs of my Hemi Dodge Ram.
Theres a reason I went for the prohibitively expensive irridium plugs!