My X-Type has been getting around 17 miles per gallon, and my range on a full tank is about 280. I was wondering if that was just the same all around. Also is there anything I can do to increase the range or mpg? I was thinking about cleaning my fuel injectors, and replacing my fuel system. Do you think that it would make a significant difference?

 

Average for stop start use.

Is 17 what the trip computer says or derived from tank fill figure?

Do you use premium fuel?

http://www.jaguarforum.com/showthread.php?t=12010

 

Lowest I've seen (trip computer....but corroborated by actual fill).... is 23 mpg on out '06 3.0 x-type. We use only premium fuel and we DO live out in the country so most of our driving is around 55mph. Not as much stop and go like city driving.
On a recent 3 hour round trip, it got as high as 28mpg.
Fresh spark plugs and very recent air filter change as well.

 

Still getting around 27 MPG in a 2001 3.0 automatic - using premium fuel and a shot of Redex every time I fill the tank - mainly urban driving with some motorway miles

 

21 urban (lots of stop/go), 26 highway. Actual math if mileage/gallins. Trip m.p.g., range off consistently between 5-10%. Premium only. With regular, there was a drop of 5-8% in m.p.g.

 

Gotta love fat fingers when typing.

 

When you say "replacing my fuel system" can you explain what you mean by that?

If the car feel like it is running properly and you have no check engine light on, then it is probably the manner/type of driving you do like others said. And also like others said use premium fuel if you are not currently. Other than that, if it is running well, not much else you can do to increase the mileage.

 

Wow I feel for you my friend.
Here in UK I have a 2.2 ltr diesel 150bhp which is enough. Town work I get 34 ish and country work near 60.
I do believe you gallon is less than ours too.
Perhaps your driving mode is a bit too "spirited"

 

17 or so in the city, just under 30 on the highway on non-ETOH gas, 320/tank.


16 city/26.5 or so highway on E10. 295/tank


2.5L, automatic

 

Got a related question and I've always wondered about the answer

Is it better to fill the car to a quarter of a tank rather than a full tank? - logically I would have thought you'd get slightly better MPG than with the extra weight of a full tank- probably not enough to make a real difference though - just not sure

 

" Fill up when your gas tank is half-full (or half-empty), because the more gas you have in your tank the less air there is and gasoline evaporates rapidly, especially when it's warm. (Gasoline storage tanks have an internal floating 'roof' membrane to act as a barrier between the gas and the atmosphere, thereby minimizing evaporation. ) "

is it true that a full tank gives better mileage? - Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com

 

Great Idea but I thought all petrol tanks were now not open to the atmosphere but sealed units so no evaporation.

 

I know there are some on here who discredit this, but I have found I get a couple mpg's better when I fill up with the ethanol free 93 octane, available nearby at a Gulf station. Mine is an '03 automatic 3.0. I average around 20 mpg on approximately 1/2 city and 1/2 hiway driving with as much as 28 on a hiway trip. One thing to remember about the amount of fuel in the tank, is your fuel pump lubricates itself better when completely submerged. When you get down below 1/4 tank, its' lubrication begins to suffer. Many fuel pumps have been known to die right after a fuel tank has been run dry. You can buy a lot of gas for the price of a Jaguar fuel pump.

 

Correct. Cars have been like this since the early '70s when EVAP systems were introduced.

The link provided above is full of pure myth and bad science.

 

Thanks guys

 

Simple math; Alcohol does not have the energy of the gasoline...but it is only about 15% of the mix (yeah, I know is says e-10, but it isn't, usually), so it really should only have about a 3% difference in power.


Most computers will crank the timing forward a bit when they sense the e-10 (actually higher octane than straight gas, a little harder to light, but better esistant to knocking), so the usual difference in practice is around a 5 or 6% drop off, but you should notice no difference in performance otherwise.


The straight super I buy is about a dime a gallon less than the E10 super, so effectively, it is a wash.


Your mileage may (literally!) vary.

 

Source please?

Again, source please? How is 91 octane E10 gas a different octane rating than 91 octane pure gas?

 

Why ethanol vs pure gasoline varies in octane. Premium here us 91 (with) & 93 (without).

https://www.google.com/amp/s/www.bel...Fhs_amp%3Dtrue

 

Yes, yes, ethanol is Satan according to at least a thousand crackpot websites, but that doesn't address my question at all.

Pure ethanol has an octane rating of 99 AKI.

 

Sourceersonally testing the tank contents at several thousand gas stations over several years for certification purposes. The gasoline and ETOH stratify in the tanks, and the ETOH has a nasty affinity for water, crud (it is a great cleaning solvent) and microbes.

Winter formulations are worse, and lean greatly towards 15%; summer formulations are generally bowsered at about 12%.

The biggest reason is that the specific gravities are different (gas at 60ºF is about .73, ethanol at the same temp about .80, simply stated, it grabs the water from the gas and it sinks to the bottom of the tank (below the sump). The initial concentration has to be higher to ensure that you get the 10% at the pump.

My only issue with ethanol is that it costs more than gasoline, and delivers less net power.

Oh, and stations hire companies (ATS is a big one) to come in and clean the critters, water, dirt, and sludge off the bottom of the tanks on a regular basis. The microbes can sour a tank of fuel in short order!