A small mystery: Edmunds and other online sources show the fuel capacity at 23.1 gallons. The Jag handbooks peg it at 21.4 — 19.8 to the bottom of the E, plus 1.6 that does not show. My experience fueling is the handbook numbers appear to be spot-on based on how much/little I can put in. Gosh — if you can’t trust the manufacturer, who can you trust. Does anyone know where Edmunds and the other online sources come up with 23.1?

I also find that the fuel-used display on the information area seems to lag by maybe one to two gallons at the halfway point — showing something in the 8-9 range. I know these calculations are kind of sloppy. It makes me wonder if that number is calibrated against the top of the red area/warning light. Does anyone know the answer to that puzzler?

Finally, when I filled my now-deceased ‘06 x350 VDP, I could probably burn a couple gallons before the gauge moved. With the 308 it starts to drop within maybe the first half gallon. Do others have the same experience?

Ah, the Jag idiosyncrasies that keep owners up at night! Thanks all.

 

I believe I found your discrepancy on the tank sizes. The 3.2L Euro/AU version has a 21.4 gallon tank...the NA 4.0L has a 23.1 gallon.

 

Many thanks. My vehicle is just under 1,000 units off the end of production. The history of fueling once I hit the red/light goes on, or getting close, really suggests this might in fact by a 3.2 fuel tank in this vehicle, though it's a NA model. I'd be stunned if there were actually approximately 5 gallons of fuel left in the tank when I hit the red. I wonder if there might be a way to tell definitively, like an easily visible part number or something that would give me guidance.

I wouldn't be surprised if the factory were using up parts that would be otherwise useless for production as they approached the end of the line. After reading the 23.1 figure my first thought was that my tank had collapsed a bit somewhere along the line as fueling numbers weren't adding up.

Thank you again for coming up with the answer on why separate figures.

 

As my Tech told me years ago, the fuel level indicator arm pivot can wear and cause inaccurate fuel levels. But in any case, the difference is only 1.7 gallons and in an elongated tank, that doesn't look like much.

 

Well, I'm reasonably certain this is the Euro fuel tank. I ran it as close to empty as I dared without a gas can with me. The fuel needle was on or just a hair off the bottom peg, and the caution light had been on since hitting the red. The message area showed 17.1G/64.8L used.

It took 18.852 gallons when I squeezed in the last ounce. That argues for the book value of 1.6G remaining below empty on the euro tank. And you're right, against 23.1, what's 1.7 gallons among friends. I just fill up 35 miles sooner, give or take, on a long trip.

In the no good deed goes unpunished department, once fueled, I could not start the car. Fortunately, the gas station guys jumped it off. The battery is 6 months old, 7 since date of manufacture. I ran the car for 90 minutes and had it tested at an Advance Auto shop -- 400 of 770 CCA capacity in it (guy said about a half charge). I then drove it another two hours (oh, darn, forced to drive my Jag again), so in theory it's got a pretty good charge on it. I couldn't get in to the shop where I bought the battery today for a check but will take it back Monday or Tuesday. There was a warning....last weekend I started getting a "check rear lights" message, but all the bulbs worked fine. I guess that's another tip-off that a battery is getting weak. The Advance Auto guy said since I generally only use the car on weekends for short trips I should just crank it up and let it idle 15 minutes or so twice a week, or take it out and drive it more,

Thanks again for your guidance.

[img]blob:https://www.jaguarforums.com/21df4ab7-cccb-44ff-b2e4-68ef68691543[/img]

 

These Jaguars benefit from the 900CCA batteries, Walmart has their MAXXH8 900CCA, or for even better longevity their AGM H8 900CCA, at very reasonable prices.

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When I first put in my AGM and rolled her over...I thought I was starting an F1 car it rolled so fast...lol
Be sure you don't have any corrosion on your cables (replace if so), that will prevent proper charging and distribution. Also check the grounds, a bad ground will not allow proper electrical flow either.

 

Yep: look for some parasitic drain or bad ground (cables hot?). Even a 770 amp battery should not drain that fast. Might have a local alternator/starter rebuilder check the alternator. In the end, 990 is better.

 

Jim and Highhorse: The battery failed a test yesterday using an Interstate-branded tester at one of the outlets of the local chain where I bought it, so it will be replaced under warranty on Friday morning. When I first had the battery checked Saturday after getting a jump start and driving it for 90 minutes, the Advance Auto gent said the alternator was operating properly.

Presuming the alternator is OK, that leaves parasitic drain as a potential issue unless the existing battery itself is truly flawed. I’ve looked at the ground strap at the battery in the trunk and it’s clean as can be. I am unfamiliar with the location of other grounding points but will do some research. I will probably have to leave checking them (if hard to reach) to my local Indy as I’m in a townhouse, don’t have a garage and my tool/testing equipment is non-existent! It’s about time for an oil change, I want to get the diff fluid replaced and I can add double-checking the alternator output, the grounding points and seeing if there’s a drain somewhere. At least his costs are about $30-40 an hour below the dealer and the other Jag-only Indy shop here.

Thank you both for your wisdom.

UPDATE — I found the electrical guide and within it find the ground point locations. I’m sure my guy has access to it but I’ll throw it in the car as a hedge. This forum is such a great resource!

 

If your guy can't find it, there is an alternator/starter rebuilder in the Merrifield area (towards the Beltway from the nursery, left hand side of the road, inbound). Rebuilds for all the local dealers and (once upon a time) Trac Auto, a local parts store. A Bosnian who survived post-Tito, but really good guy and helpful.

 

Hey, thanks. I'm over in Annandale so this is right around the corner from me.

I'm getting the new battery under warranty this morning at VA Tire & Auto. I'm going to ask them to doublecheck the alternator output. Next step is to drive the car more frequently, then if needed ask my indy to put the car to sleep and see if he can find any drain.

Happy motoring.

 

The car itself should go to sleep 2 minutes after the door is closed...or you can leave the trunk and/or door open and let it sit about the same time. If you put a meter on it before it shuts down, you can monitor it.