Having completed treatment and rinse phases in this car and now it's back running on fully synthetic Ii decided to track MPG variations on a regular drive.
I undertake this drive in identical test conditions (as I always leave late evening or early morning when it is cool and no traffic).
model year 96 (in the uS you say MY97) with a replacement engine in 2004 30k miles on new engine External Temp = 5-10 degrees C mileage distance = 350 (2 x 175) duration of each leg = 3hrs 10 mins Gasolene = 100 RON (super unleaded note in the USA I think that's 97.7 MON) No stopping excepting at end of each 175 mile journey Both cold starts (as I'm visiting my Mom I have to stay don't I!!)
Previously I was achieving 28.2-30.1 MPG and in the two most recent runs since the ARX treatmet I've achieved 33.4 MPG and 34.1 MPG
Now previously I thought I'd been getting good gas mileage for a 4ltr V8 but now with the increase averaging 4.5MPG (circa 15%) I reckon that's close to an extra 75 miles per tank.
I'm shortly to convert the Jag to run on LPG which should mean that I can do the same journey at half the cost. UK super unleaded costs £1.04 UK per litre or $1.97 US so to fill up at this rate stateside would cost you circa $74 from empty (So think about paying $7.48 a gallon the next time you complain about gas prices!)
Note that to fill this car with UK gallons =16.5 which equates to 19.8 US gallons...nice to have something in the UK that's bigger than you have across the pond!!