I hope I am not jinxing myself, but I thought I'd post some good news for a change. Usually when I post is if I have some issue I need addressed on the car, but this time I thought I'd just report that she is driving great! I use her as my daily driver (~30 mins one way), and she has been most reliable. I just put new Pirelli P4 Four Seasons on her and that has smoothed out the ride that little bit more. I'm averaging ~17mpg (which is still painful, but on these cars sounds like about the best I can hope for) which is no highway, but 65~75% fairly open 2 lane road and the rest in town.

Other than fuel economy, or lack thereof, I can't really complain. I wouldn't mind an XJ12 sway bar to lessen body roll some (is there a rear sway bar option or would that upset the balance?).

Anyway, thought I'd post some positive comments.

Take care,

Eric

 

The best I ever used to get on fuel mileage with a Series 3 4.2 was about 18 mpg on a UK gallon, so as the US gallon is smaller, your 17 mpg looks about right. I don't think you will ever get better than this.

Glad your's is reliable. I managed to get my car to a fairly reliable state, but it took 14 years ! Mind you it was a 1980, the absolute WORST year for Jaguar quality in my opinion. although previous years in the 70s were pretty much the same.

 

Some of the XJSs had rear anti rolls bars....which would work on your XJ6. There's aftermarket bars out there as well. Google "Driven Man", I think


Cheers
DD

 

Thanks for the comments. What's the deal on the low fuel economy anyway? Is it all down to the weight of the car? I hear about E-types with more horses and better fuel economy with carbs rather than fuel injection. Obviously they weigh less, is this the only difference or am I missing something? What does an E-type weigh compared to our XJs?

Doug, I actually was emailing the "Driven Man" last night about rear sway bars, but he claimed the rear XJS bar he has won't fit the XJ6. I thought the chassis were very similar, just one shorter than the other. Any thoughts?

 

Looking at test reports from the 80's, the fuel consumption was about the same when the cars were new....
Mine is only averaging about 15-16... but I know that I have an issue with running too cold, most likely resulting in overfueling....

I can say this, My wife's Dodge went into the shop in early September, forcing her to drive my 84 everyday... and after several weeks of it being a dedicated daily driver, it's actully running better than ever. There have been a few hickups, but all in all nothing that couldn't be fixed easliy.
I read a long time ago that these cars were meant to be driven... and I've noticed through the years that all kinds of problems come up when they sit for a while... But now I'm glad our's is really an EverydayXJ...

David
Everyday XJ

 

Three simple words explain the primary fuel economy problems with these cars. They are "three speed automatic". I'm quite confident that with a 5 speed manual behind them they could turn in the low 20s on the highway.

 

That is a very good point. You are correct, the tranny in these cars is not helping out the fuel economy at all. Does anyone on here have an XJ6 with either the newer tranny swap from John's cars or a manual swap? If so, what kind of mpgs are you seeing?

 

The old E-types weighed about 2800 pounds, I think. Versus 4100 pounds :-)

My Ser III would get about 12-13mpg in the city and about 19-20 on the open road. Sometimes 21+ if I was very gentle.

The weight, aerodynamics, elderly engine and fuel injection deisgn, and inefficient trans all play a part.







Hmmmm. Odd. The chassis are virtually identical.

I've heard from guys have have used OEM XJS rear bars on a Ser I-II-III XJ6 with no problems. Perhaps the aftermarket stuff that driven Man sells is different? I dunno. I find it a bit hard to believe <shrug>

Cheers
DD

 

Quite a few guys at Jag-lovers have made the swap to the 700R4/4L60 trans and are very happy with the improvement. I can't remember any fuel econonmy specifics, sorry, but it would almost certainly have to improve.

Cheers
DD