In case you haven’t read it, I’m using this article as a point of reference:
I’m attempting to make my 1990 3.6 auto a hypermiling GT. just like Johns…
Has anyone attempted what John has done to his XjS?
Or indeed, John, are you on here?
Any ideas that are contributed that puts the mpg up are much appreciated 
Love this crack…
“The body shell is stiff and commendably light, even if Jaguar then filled it with components apparently made from depleted uranium and osmium.”
LOL!!!
A lot of rhetoric in my opinion…
The article is certainly talking about Imperial gallons, not US gallons, so the improvement is more like 35-36 mpg by US standards. I may have skimmed the article too much but I’ll bet that’s steady state highway mileage, not a combined city/highway driving cycle.
Dave
It is.
Interesting project. Most of the ideas are good, although I suspect some are more worthwhile than others. I thought the oil cooler scheme was interesting; I’d never seen an oil-to-water cooler that sandwiches under the spin-on oil filter. Sounds like a good idea, and a far better idea than, say, trying to convert a bypass flow scheme to full flow on the V12.
He’s talking in GBp so I would be inclined to think its Imp MPG
DOH just re-read your comments 