[Mk2] [Turbo] Bad Fuel Economy ? potential issue ?!

[SonicSW20]

FYI MR2 MK11 has a 55 litre (12 gallon) tank

True but some of that is not usable. The reserve light comes on when it takes about 40 ltrs to fill the tank.
(dont assume the reserve light will always work).

Not usable?

The light is simply a low level light. There is no 'reserve' tank.

I actually ran out in my old MR2 once. On filling up, it took ~54litres of fuel.

It's certainly useable, you would be silly to try and use all of it though! I got caught out as the light had failed, and I hadn't realised.

For the record, the car was absolutely fine afterwards. Claims of 'crud' in the fuel tank being an issue are FUD mainly. Have you actually looked inside a fuel tank? They are usually very clean as petrol is a very good, but dangerous, cleaner! Also, the pickup has a mesh cover, and you have a fuel filter.

[rev3gtturbo]

An easy consistent 30mpg seems high. You must have a light foot or a car eager to please!.

I am no racing driver, and I am no slouch either (which seems to annoy some drivers of beemers and audis that expect an old mr2 turbo to be slow and get shown different )

Go back about 10 years and I think I drove these cars the same way and got 24 mpg. So what has changed? Fuels getting better? Tyres getting better?

Yeah the mr2 is a pleaser as well

[rev3gtturbo]

FYI MR2 MK11 has a 55 litre (12 gallon) tank

True but some of that is not usable. The reserve light comes on when it takes about 40 ltrs to fill the tank.
(dont assume the reserve light will always work).

Not usable?

The light is simply a low level light. There is no 'reserve' tank.

I actually ran out in my old MR2 once. On filling up, it took ~54litres of fuel.

It's certainly useable, you would be silly to try and use all of it though! I got caught out as the light had failed, and I hadn't realised.

For the record, the car was absolutely fine afterwards. Claims of 'crud' in the fuel tank being an issue are FUD mainly. Have you actually looked inside a fuel tank? They are usually very clean as petrol is a very good, but dangerous, cleaner! Also, the pickup has a mesh cover, and you have a fuel filter.

I never said there was a reserve 'tank'.

The tank has a 55 ltr capacity in my owners manual and you found you could not put 55 ltrs into after it ran out of fuel so there must be a bit that was still in there (the unusable bit!). Ok so it may be less than 1 ltr but it is still an unusable amount of the tank capacity. (I have known some fuel systems where the owners manual says that 3 ltrs in each tank is unusable and the required maintenance schedule states when it is required to clean out the fuel tanks, ok that was for a small aircraft and not an mr2 so not a fair comparison )

It is best to assume fuel gauges (and low fuel warning light) are inaccurate and unreliable and then nobody should run out of fuel.

I never try to run it that low. I usually fill it up when the trip meter indicates it will take 40 ltrs to fill it (or the low fuel light comes on significantly early). I would not wait for the low fuel light before putting fuel in it because one day either the sensor or the bulb will fail.

As I fill the tank and reset the trip meter, I can become familiar with when my low fuel light would usually start to flicker and if it were to come on way too early it could be a sign of a fuel leak or engine not running as efficiently (assuming not on a race track instead of the roads).

Anyway, 30mpg can be regularly achievable on a std power rev3 turbo.
There are many factors affecting fuel economy. The original question was about 21 mpg which seems way too low if it is a std power mk2 turbo.