Jake, I also have a '97 VDP but mine has the "Andy Bracket" on it. Around town I consistently get 18 to 19 mpg running on the suggested high test (trying here to stifle snickering and outright laughter) gasoline. On the interstate I get 26 to 29 mpg with the converter locked at about 2500 rpm at 74 mph. Maybe you should consider replacing your cps bracket with one of Andys. Easier starts, more pep, easy install. Also, does your converter lock ? Mine drops the rpms when it locks up at 52 mph at normal operating temp.

 

Zathras,

about 3.8 litres = US gallon
4.5 litres = imperial gallon.
your car and mine are in Imperial gallons

I run 98 Octane (BP) which I am fairly sure is shipped in from Singapore refineries. I get about 20-22 mpg on my commute (3 miles to warm up engine, 8 miles warm, then same home again). Warmed up with the aircon off, I can get about 25-6 mpg, but it doesn't concern me that much and I like to give Ol'Blue some stick, so I average 20-22
The Shell/BP 95 does well.
the only NZ fuel with ethanol I am aware of is Gull. I avoid it - it can dry out old rubber seals etc. I foolishly put a bit in my dad's 1928 Alvis, last year. It went right through old leather fuel seals like a dose of salts, leaked for a couple of months and took a lot of effort to sort out.

I add a bit of TC-W3 outboard 2 stroke oil to the tank when I remember, about 1.6 mL per litre of petrol. It cleans the top end and does no harm.

 

I live in the Phoenix, AZ (USA) metroplex. Today for premium fuel I payed $3.41 As for MPG around town in city traffic I average about 16. On a recent trip from Phoenix, AZ to Las Vegas NV, about 399 miles, I got 23.3 up and 26.0 on the return. The speed up was on cruise at 65 MPH and the return was 68-75 depending on the speed limit.

 

I live in the Phoenix, AZ (USA) metroplex. Today for premium fuel I payed $3.41 As for MPG around town in city traffic I average about 16. On a recent trip from Phoenix, AZ to Las Vegas NV, about 399 miles, I got 23.3 up and 26.0 on the return. The speed up was on cruise at 65 MPH and the return was 68-75 depending on the speed limit.

 

The US market cars use US gallons, the rest of the world cars use imperial gallons.

To answer why different gallons, I need to give a short history lesson. In 17th and 18th century England the size of the gallon was different depending upon what you were measuring. There was a wine gallon, an ale gallon, a beer gallon etc and all were different. In 1824 a new Weights and Measures Act was passed that was a major overhaul of the units of measure. Many old units were made obsolete and those that remained were simplified. For example there was now only one gallon, an Imperial gallon, as the new system was called the Imperial system of measure.

However, the USA had broken away from Britain before this took place, and when they were founded they used the English units of measure at the time and never updated them. Thus the US gallon of today is really the Queen Anne Wine gallon of 1707.

The 1824 act also changed ounces, so a US gallon is 128 pre Imperial ounces, and an Imperial gallon is 160 oz. Each gallon has the same number of pints and quarts, but each pint and quart is a different size between US and British systems. If we switch to metric (litres), the ratio of Imperial/US is 4.54/3.78= 1.2, but if you do it in ounces you get 160/128= 1.25, showing the ounces are not the same.

So to summarize: In the US, use the English 1707 units. In the rest of the world use the Imperial 1824 units, unless you have a more modern Jaguar. For some reason my 2007 Canadian market X Type uses US gallons on the trip computer, while my 1995 XJR uses Imperial gallons. Since US measure has never been used in Canada I have no idea why Jaguar switched on the later cars. I wondered why the fuel consumption seemed so bad on my X Type until I realized it wasn't using real gallons!

 

Wow. That is enlightening and terrifying. I think I might stick to l/100km instead

 

Yea I emailed him for ordering info. I plan to buy a bracket.. this is to only real answer to my original question? I was just fishing for anything else or learn about another upgrade i was missing or anything else to try for better gas mileage?
tks bro

 

Bottom line IMHO, if US folks are seeing anything north of 20MPG on the highway, they should count their blessings

2 ton supercharged 320HP car, getting almost 30MPG on the highway for some of you is pretty impressive.

I am happy to get mid 20s on the highway with my 1995 SC Riviera, and low 20s with my 1995 Roadmaster.

As inexpensive as these cars are on the used market, mid 20s highway MPG is totally acceptable from a operating expense perspective (fuel anyway)



.

 

BTW, what isn't clear to me from the various MPG and imperial versus US gallon comments..... do the US XJs trip computers properly display MPG in US gallons?

 

Yes!

Cheers
DD

 

Great, that would be inconvenient otherwise

 

Andy is no longer making his brackets.

 

True, but he also is "keeping a list" of those that have inquired just in case he changes his mind, and he's up to about 15 or so at this point, maybe more.

If you are interested, I'd suggest at least letting him know.

I know that I for one would be happy to pay a reasonable premium over his previous asking price to get them back into production

Al

 

Advancing your timing using the bracket won't make much difference, just increases low end torque!
Anyway I get 25 round town and upto 35 mpg on long runs (uk) - this is after I cleaned the engine (de coked) whilst replacing my head gasket.
Do you have terraclean in the us - might be worth a try

 

I've read about the Terraclean and it does sound interesting, but can't find any US locations off hand. I've dropped them a note to see if there are any in the USA.

Also, I do think that some folks have reported increased MPG with Andy's bracket.

.

 

Try a bottle Chevron's fuel system cleaner "TECHRON" - it's pretty good at decoking your motor. It has the highest PEA ratio of all the additives and will get rid of carbon in the intake and combustion chambers as well as around the injector nozzles and valve stems.

Do the treatment then change your oil and filter as a lot of the crap removed will end up in the sump.

Sure made my XJ40 run like a bird.

happy motoring

Larry

 

Yeah, I had read somewhere that "Techron" was one of the few additives that does much of anything, so I put it in my cars every year.

.

 

I filled up the '97 XJ6 L with 91 octane and hit the road. With the car full (3 passengers, 3 suitcases, 1 chainsaw, a number of other misc. bags, etc.) I set the cruise at around 75 on the Interstate. After around 300 miles or so I'd averaged a little better than 23mpg - better than the Kia minivan!