Mazda 3 2014 - fuel tank capacity lower than stated?

Nasqueron

Hopefully a quicky.

I have a Mazda 3 64 plate (2.2 diesel, 150ps), stated fuel tank capacity on Mazda website is 50l.

I have NEVER, even when tank is 99% empty (estimated range is 0 and driven 3 miles to the garage sort of empty) managed to put more than 43L in. Typically when it's on the last bar of the indicator (it has a digital representation rather than the moving arm) I go to fill up with range on about 10 miles and get 40L in.

I don't especially mind, it's just odd as I'm getting about 415 miles out of a tank (averaging 45.6mpg at the moment) and my old 206 also had a 50l tank and that I always seemed to get in 52-53l before the pump cuts out and got about 550 miles out of a tank).

Any thoughts?

neilmcl

You're never going to prove exactly what the capacity is unless you're prepared to run the car dry and fill up to the brim, something you're not going to do, particularly with a diesel, so I can't see how you can say that it isn't a 50L tank.

kev25v6

Just do more miles when it says 10 left to empty and you will get more fuel in the tank. The gauges are never that accurate, all based on average consumption. If you run to completely empty and its a diesel, expect it to be a nitemare to restart. Why let it run to that low anyway?

Nasqueron

kev25v6 wrote: »

Just do more miles when it says 10 left to empty and you will get more fuel in the tank. The gauges are never that accurate, all based on average consumption. If you run to completely empty and its a diesel, expect it to be a nitemare to restart. Why let it run to that low anyway?

It varies Kev, if I have offer at supermarket (double points thing) I fill it up on the last date of offer regardless of what is in the tank for example. I don't normally let it run that low, the 0 range was a one off due to circumstances. I tend to plan a garage trip when the light comes on, I just like to know approximately (for a worst case scenario) what range I can expect and given that a 50L on my 206 was easily taking 52 on low, being 7-10 litres short of capacity seemed a bit odd to me

photome

My ceed has a 53l capacity, I can squeeze about 45l in when its empty but takes ages, dont let it worry me though

Nasqueron

neilmcl wrote: »

You're never going to prove exactly what the capacity is unless you're prepared to run the car dry and fill up to the brim, something you're not going to do, particularly with a diesel, so I can't see how you can say that it isn't a 50L tank.

I am not saying definitely not neil, I just wonder as I got the 206 at 1 year old and never had any issues putting in close to 50l when it got low, this one saying it is empty and being 7-10l short of capacity when the nozzle cuts out seems odd and does does mean a few more visits to the garage.

50L tank = 10 gallons

At 45.6mpg I should be getting 456 miles from a tank but 400-415 is normal (unless the tank has really got 7L more in there and car is talking nonsense) so it's just a guess, just not come across is before

forgotmyname

Gauges and sensors are not 100% linear. Park on a slope and it will usually register a different amount of fuel in the tank.

When the 206 said it was empty it was probably very close to being empty. Your Mazda probably has a couple of gallons left over even after it says zero.

The trip mpg is an average, I presume you were not at a steady cruising speed when it said zero left.

I came out of the works carpark having to unlock and relock the gates, As i started it from the car park to drive upto the gates it said 13 miles left.
After locking up and sitting in the traffic to the lights up the road, it had changed to zero miles left.

After a few miles on the 40mph dual carriageways that were fairly clear it had increased to 13 miles again.

uncreative

for a diesel I was always told to fill up once it hits the quarter left. You dont want all the crud that settles on the bottom of the tank getting concentrated and sucked into the fuel lines / filter.

Also, there is a prepper school of thought that you shouldnt let it go below half in case of a national emergency/zombie apocalypse you will always have at least 200-250 miles of fuel.

Or you should fill up to the half so that you get better mpg as not lugging around an extra 30 or so KG of fuel.

Who knows but I always fill to the top and never let it get below the quarter.

kev25v6

Easiest way to know what you get for a normal tank is fill to the top, run your usual weekly trip(work,shops, visiting etc) and then refill after 300 miles and calculate your average mpg from that. Most average cars will do 400 miles on a tank. I always fill up on Wednesdays just because I pass sainsburys on that day and their super is only a few pence more than standard fuel.

marlot

Nasqueron wrote: »

...
I have a Mazda 3 64 plate (2.2 diesel, 150ps), stated fuel tank capacity on Mazda website is 50l...

My MX-5 is the same. I did once get 47 litres in there, and hadn't run out, but the guage reads zero from about 43 litres and the low fuel light seems to come on very early.

I assume its just Mazda's way of 'protecting' us.

scotsbob

marlot wrote: »

My MX-5 is the same. I did once get 47 litres in there, and hadn't run out, but the guage reads zero from about 43 litres and the low fuel light seems to come on very early.

I assume its just Mazda's way of 'protecting' us.

You beat me to it! I also have an MX5. The gauge plummets from full to half at an alarming rate, then takes forever to go from half to empty.


I guess it's just a Mazda thing.