OK, so I only get to drive my car sporadically during the winter and I had it out again today. Since I hadn't filled up in a long time and I was getting to about 5/8 full, I decided to top off since I figure it's better to be full when stored in the garage and to also get some fresh V-Power in the tank.

The pump "clicked" on 3.2 gallons, and I thought that was way to little gas because that calculates out to 26.5 mpg which I know is wrong (no frickin way). I even hit the pump again to see if it would continue to fill and the pump "clicked" again so I said fine, I guess that's enough.

When I drive off, the gas gauge does not show full. Since I know I usually get around 18 mpg, I figure the pump stopped me short roughly 1.4 gallons or so. Was it the pump or the car?

Normally when I fill up when I'm close to empty, I am able to completely fill the tank so my gauge shows completely full. Anyone else experience this when they fill up with over a half tank left? Just curious...

 

I've never fueled up that fast before. I try to go as l-o-n-g as possible between fillups :D

 

I've often filled up with less than half a tank. It doesn't seem to matter at all.

It's been a bit of a project of mine, but my 8 is completely predictable on fuel consumption. All highway = about 22/23 mpg. Three-mile commutes back and forth to the local train station, about 15/16 mpg. Since my driving is almost never one or the other, it bounces around... check out the spreadsheet for details. Two dates to compare: Sept. 14, 2004 (7 gals./all highway, 23.4mpg) with Oct. 30, 2004 (7.4 gals/mostly commuting, 15.3mpg).

 

Did the pump you where using seem to dispense fuel very quickly and did you have the lever completely depressed? I had this happen a couple of times and I think the pump dispensed fuel so quickly it acted as if the tank was full. I have also filled the tank numerous times when above half and it doesnt seem to affect it.

 

You guys are lucky. In nj its illegal to pump your own gas

 

I had this happen once. It was the pump or I was parked on an incline when I was fueling. I never let mine get lower than 1/2 and try to keep it full since I am like you. I wait for a nice day before I can drive it in the winter. It mostly sits until the snows stop for the rest of the year. That's likely in May sometime. I have not had that happen again.

 

Happened to me all the time with the Miata. At best guess, there's simply some gas (air) under pressure inside the tank. When you start pumping, it's all suddenly displaced, and trips the pump cutoff. Really got on my nerves when it happened... Wasn't very predictible, either.

 

um it happeneds to me all the time.... both ML430 and CLK320 always does that for some reason... they always stop and think it's full or something but it's actually not full yet.... i thought it was the design of the fuel tank taht the gas may be going in too slow and chocking the pump but i never knew waht it was...

 

FamilyMan,

Was the car running when you were filling up? I have had the pump shutoff easly when i left the car running when filling it up. That's the only time I have experienced it.

 

for those of us with winter, it is recommended to keep fuel full for two reasons, a. if you get stuck the car is the only source of warmth and you need the engine running to get heat, and b. condensation occurs in the cold and since water is heavier than gas it sinks to the bottom and starts corroding the fuel tank.

 

15.3 mpg is almost exactly the published spec. Mine is lower but I'm attributing it (for now) to the extreme cold -- betweeen -20 and -40 Celsius since Christmas, which is when I got the car.

 

No, 15.3 is *not* "almost exactly" 18. Remember, we use US gallons, not imperial gallons. US published spec with US gallons is 18 city / 24 highway. The much-lower-than-published economy is what people are complaining about.

 

read the range for each number on that window sticker

 

Nope, the car wasn't running... unless it happens again, I guess at this point there is no harm in it and that it was probably some combination of the pump and the cold weather.

I did make sure I put my gas cap on nice and tight though...

 

I would say that the pump was dispensing either quickly or about normal. Yeah, I did have the lever completely depressed, and after the first click, I paused briefly, completely depressed the lever again, and the pump clicked on me again, so I quit trying to put more gas in it. It wasn't until I drove off that I noticed the gauge didn't real 100% full.

 

Wow... that's quite a spreadsheet.

 

Yeah, that's for 'other vehicles in this category' to let you know how this model compares within the market segment. A Mazda3 would be in the same category as a Civic, a Focus and a Golf, among others. A Mazda6 would be in the same category as an Accord, a Camry, etc. I'd be interested to see what other vehicles are in the RX-8's category.

The 'big' numbers (18/24) are for what THIS MODEL showed in testing by the EPA.

 

I didn't know that about NJ (I lived there for a bit). The last time I was there I almost punched out a gas jockey in Newark. He came over to the car I thought he was a mugger.

 

Actually, the 18/24 is a percentage off the EPA numbers. Believe it or not, those EPA numbers already take some percentage off their true numbers, to account for variation (I think it's 15%).

As for the problem described, I have it every once in a while here in Cali. The specific pump head was probably brand new. I've had a pump kick back every .3 gallons. It's easier to tell when the gas is way low, if your tank is half full you don't know if you got great mileage or what.