My MX5 SVT with turbo and ecu - mpg issue

[hinikuru]

The initial message was deleted from this topic on 12 May 2011 at 22:39

[franv8]

Guesstimate suggests that's just shy of 30mpg. My Mk 1 always does this at best, normally 27, and that's a stock 1.6.

I think the Mk 2's were a bit better, low to mid 30's, but you are on a turbo and your management probably richens things up a bit + you'll probably use it!


Sounds in the normal range for type of car to me,

HTH

[piefacemate]

I get 150 per tank, sounds like you're doing ok.

[hinikuru]

Ok cool thanks guys

[MX-5 Lazza]

Miles per tank means nothing - when do you fill up? It's a 50 litre tank and the empty mark on the gauge is nowhere hear empty in the tank. I've gone 70 miles after going below E in the past. How many litres do you put in when you fill up?

My own supercharged car is well tuned for power but I still haven't tuned for cruise so it's uneconomical at the moment but I still get over 200 miles to a tank. Does your car have an AFR gauge?

[hinikuru]

I ll get about 220 after about 25 miles when the fuel light comes on I fully refuel for.

[MX-5 Lazza]

Well next time you fill up take a note of the miles and the litres then try the following calculation:
(miles/litres) * 4.54 = mpg, so in your case if it's 220 miles and 40 Litres it will be (220/40) * 4.54 = 24.97mpg. If your cruise is well tuned and you keep out of boost you should be able to get 30+mpg.
No AFR gauge then?

[GravelBen]

My Mk1 1.6 turbo will do 35+ mpg easily enough on the open road, it doesn't seem too unusual for a well tuned (ie standalone ECU not piggyback) turbo MX5 to be more economical than standard when cruising.

[hinikuru]

I ll get about 220 after about 25 miles when the fuel light comes on I fully refuel for.

[JonnyFive]

220 miles to a tank on a Turbo? No problem with that.

I get about 220-250 before I fill up which is at (E) on a normal 1.8 N/A engine.

[MX-5 Lazza]

hinikuru said:

I ll get about 220 after about 25 miles when the fuel light comes on I fully refuel for.

You said that before but without knowing how many litres you are putting in that means nothing.

[JonnyFive]

MX-5 Lazza said:

hinikuru said:

I ll get about 220 after about 25 miles when the fuel light comes on I fully refuel for.

You said that before but without knowing how many litres you are putting in that means nothing.

Got to be about 35-40L hasn't it?

[MX-5 Lazza]

JonnyFive said:

MX-5 Lazza said:

hinikuru said:

I ll get about 220 after about 25 miles when the fuel light comes on I fully refuel for.

You said that before but without knowing how many litres you are putting in that means nothing.

Got to be about 35-40L hasn't it?

It's a 50L tank. Mine doesn't have a low-fuel light so I don't know when that comes on.

[hinikuru]

Hi

Sorry Yes it's a 50l tank.

Thanks

[JonnyFive]

MX-5 Lazza said:

JonnyFive said:

MX-5 Lazza said:

hinikuru said:

I ll get about 220 after about 25 miles when the fuel light comes on I fully refuel for.

You said that before but without knowing how many litres you are putting in that means nothing.

Got to be about 35-40L hasn't it?

It's a 50L tank. Mine doesn't have a low-fuel light so I don't know when that comes on.

Neither, my chaps here reckon its about 8-12L when the light comes on.

[LukeBird]

MX-5 Lazza said:

It's a 50L tank. Mine doesn't have a low-fuel light so I don't know when that comes on.

On my Mk2.5 it typically comes on with around 8-10 litres left.
When I filled up last I managed to squeeze 41 litres in (at the hideous average of 22.5MPG!!) and the light had been on maybe 5 miles or so.

[carmadgaz]

My stock mk2 1.8 manages between 28 and 32 mpg over a tank depending on how hard she's being driven so with turbo and bits your consumption seems reasonable.

[cyprinis]

Do UK mk2's have a fuel light?

[JonnyFive]

cyprinis said:

Do UK mk2's have a fuel light?

No.

Late MK2.5 did though

[Mr MXT]

What turbo kit and what management?

Tbh I'd be over the moon if I got 220 to a fill up!

I usually get around 20mpg!