Fuel consumption conflict???

Chiggles · Post by **Chiggles** » May 8th, 2005, 1:37 am

So I'm flipping through the pages of my owner's manual today to look up something and I came across a page that lists some of the fluid capacities of the car. In particular, it states that the fuel tank is supposed to fit 50 litres of gas (or 13.2 gallons for those of you in the US). Why then, when I fill up the tank at the gas station from bone dry (indicated from when the fuel light in the gauge panel lights up superbright) to the point where it's so full that I can see a bit of gas floating around at the opening, that the pump says I've only put in about 38 litres of gas??!?!

Where the heck does the other 12 litres of gas go to?? That's a lof of missing fuel that I could be using!!

V8KOMX3 · Post by **V8KOMX3** » May 8th, 2005, 2:06 am

I wondered this as well because I drove my car to empty 1 time so I knew how far I could go if it was an emergency or something and when I filled it it only went to a little over 11 gallons but my thought was that the rest was in fuel lines and such but thats alot of fuel

Thunderstorm · Post by **Thunderstorm** » May 9th, 2005, 10:05 am

I have a 1998 RS - it has the singular dubious distinction of NOT having a fuel gauge warning light.

I am limited to watching that needle drop till it is "on the floor" and so far, I have yet to run out of fuel - but I digress....

I believe most cars are fuel warning systems are designed so that when fuel is down to the last (approximately) 20% capacity (in the case of our MX-3's) the light comes on. Now this gives you enough fuel reserve to make a bee-line for the nearest Gas (Petrol) Station and make it with enough to get to yet another if that one is off-line.

The large reserve comes into its own if you were on a motorway, and the next Gas Station was 50 Miles from your location. I presume you understand the logic to this.

It doesnt matter much when you have 5 or 6 Stations dotted around, within 3 miles of your home or work location. But those who regularly find themselves in the middle of nowhere will find that large reserve and early warning capability a godsend.

Usually I end up filling up to the brim with anything from 38 Litres to 43 Litres. By the time I get to the latter, I have really been riding around with my heart in my mouth & the car metaphorically running on Gas Fumes.

Hope this helps in some small way.

Thunderstorm

RoundTop · Post by **RoundTop** » May 9th, 2005, 1:51 pm

I've also got another wonderful "no gas light" MX-3.

when it hits the E line I figure on it having 12L left. Which is enough for over another 100km (60 miles)

Just drive a bit more before you fill up.

jordan69 · Post by **jordan69** » May 9th, 2005, 5:06 pm

that is somewhat of a safety feature so you have PLENTY of warning time before you ACTUALLY run out of gas, see, already saved you guys from running out of fuel, and its also not very good to run a fuel pump dry because its hard on it, especially in summertime when fuel pumps cavitate alot easier.

snellgrove · Post by **snellgrove** » May 9th, 2005, 5:24 pm

yeah, no light here either..

I let it reach 'the bottom' (of the gauge anyway..) and theres always loads in there...

working out my MPG, I should be able to do a whole bunch more miles than I do on a single tank...

johnnyb · Post by **johnnyb** » May 9th, 2005, 6:09 pm

you sure you guys dont have a light? It doesnt go on till it hits E or lower.

I've fit 42L in my car before

ManoWar · Post by **ManoWar** » May 10th, 2005, 1:00 am

ok i will test this cuz its bugging me aswell. Will go to gas station and get in a container 10L. Then i will drive it till it stalls.

I will record the results and post em here. Without pushing it to see how many more km i go from the first time the light goes on.

mitmaks · Post by **mitmaks** » May 10th, 2005, 1:12 am

I thought GS only had 9. something gallon tank, under 10 gallons

Tunes67 · Post by **Tunes67** » May 10th, 2005, 1:21 am

According to everything I could find on the MX-3.. they all came with the same size gas tank. 13.2 US Gallons. On my car.. only 10 Gallons show on the gauge.. using the fuel indicator light as a guide.. (once it comes on and stays on even when going around corners) I can typically only fit 10-10.5 gallons into my tank at that point.

Tunes67

ManoWar · Post by **ManoWar** » May 10th, 2005, 12:12 pm

mitmaks wrote:I thought GS only had 9. something gallon tank, under 10 gallons

A friend of mine told me that the 93-92 GS came with a 35L tank

mazdubber · Post by **mazdubber** » May 10th, 2005, 7:51 pm

In my 1992 MX3 owners manual it says the capacity is 50 litres. I've found the light to be pretty sensitive. When you are on inclines or go over bumps it tends to flicker on and off. I once had the light come on when I had about 100km's to go and not a penny to my name to fill the tank! I was just a starving racing school student.

I made it home and even made it to the gas station the next morning! I have driven the car to the point where the engine started to sputter. I would say that that is the definite empty point. I managed to get about 44-45 litres in the tank. I think there is a pocket of air at the top of the tank that can't be filled by gravity because of the location of the filler on the tank. You could probably get 50 in if you pressurized it. But that would be a bad idea.

Chiggles · Post by **Chiggles** » May 11th, 2005, 3:15 pm

Glad to know it's not just me with the 38L tank issue. I didn't think the light came on at a point that has such early notice though. I mean, if you guys say you can get another 100kms out of the tank when the light comes on, that seems like a HUGE early warning to me. For me, when I run the car from full to the point where the light comes on and shines its brightest luminence possible, that 38L gives me about 320kms (city driving, not highway).... so that extra 100kms you can stretch out after the warning light comes on would work out to be almost another 1/3 of a tank compared to what the gauge can read. Based on that, you guys seem like you're suggesting that there's still enough remaining gas in the tank that you can run the needle down PAST the "E" on the guage by almost another quarter inch. That seems odd to me that we can push the needle that far past the intended "bottom line".

ManoWar · Post by **ManoWar** » May 12th, 2005, 2:39 am

Ok i refueled today
Light came on at 420 kms
Drove it till 609km's and i managed to squeeze in 46L

neutral · Post by **neutral** » May 12th, 2005, 7:05 am

Closest to empty I ever pushed a 100% full tank of gas was

-390mi/627km
-Refill was 12.1 US Gal/45.8L
-32.23mpg which is typical mixed-driving mileage for me
-Warning light started flickering on @~315mi/499km and was on constant solid bright @355mi/571km

Fig I've got a max of ~100mi/161km with gentle driving once the light first flickers on/off. Seems like a very early warning threshold but agree w/Tstorm - gas stations aren't always within a few miles. I recall a stretch of I70 (in Indiana?) where exits are 70+ miles apart & driving across the Shasta Mtns in No. Cali didn't see a gas station for similar distance.