28mpg!!

[attym3]

So I've had my Eunos about a month now and I thought I'd work out my mpg. I was hoping for 35-40mpg but it's just over 28mpg! This is half quiet driving and half on it
Should I expect better?
Thanks

Mark

[Munter]

If it's a MK3 that's a bit disappointing.

If it's a MK1/2 that's about right. 30mpg is what I tend to get at best.

[attym3]

Munter said:

If it's a MK3 that's a bit disappointing.

If it's a MK1/2 that's about right. 30mpg is what I tend to get at best.

Should have stated Mk1 1.6

Mark

[MX-5 Lazza]

'91 Roadster according to http://www.pistonheads.com/gassing/topic.asp?h=0&a...

Should do better than that. I take it you worked it out right i.e. (miles/litres) * 4.54?

On a run up to Norwich & back at the weekend I managed 29.5mpg in mine though half of that was sitting around in traffic (which mine really doesn't like) and the other half was trying to make up for lost time Bearing in mind the mods on mine I'm pretty happy with that.

[JonnyFive]

Yep, 28mpg is about the same as mine too

[skinny]

depends on the conditions too. probably not too bad if you're doing a lot of short journeys but if there's a few motorways in there then that's looking a bit low.

you're gonna struggle to hit 40 tho.

[Gizmo!]

Well done!

Now you've had it a while, you can start driving it properly.

[NiceCupOfTea]

Sounds about right.

[tali1]

Every car has a couple of owners who thrash their cars AND get miracle economy -there has to be a 40mpg MX5 owners lurking out there

[_Batty_]

I get 400kms out of mine regardless of how I drive.
No idea what mpg that is!
(early mk1 eunos)

[NiceCupOfTea]

High twenties I reckon. I get 350-400kms to a tank. 400km is 250 miles, and I usually get about 40-45 litres in the tank when it's empty. I get about 25mpg on average - best ever is low 30s on a long mway journey at 60 or so. 40mpg is a pipedream in a Mk.1! (mine is a 1.8).

[attym3]

So why are they so bad? It's only a 1.6, I get the same if not a bit better out of my 3.0 M3!

Mark

[Munter]

attym3 said:

So why are they so bad? It's only a 1.6, I get the same if not a bit better out of my 3.0 M3!

Mark

You have to consider that the MK1 was designed in the 80s. The ECU is not as clever as later cars, and the engine was originally designed (before being heavily tweeked), as a turbocharged engine in the 323.

Also look up open loop. Where at over 4000RPM (i think) the mode the ECU runs in changes: http://forum.miata.net/vb/showthread.php?t=382400

[Toro Rosso]

On the last tank of fuel I put in (which is the first I measured properly) I got 29mpg on a '95 1.8 with 77k. It has been serviced since, so hopefully may improve slightly. I would say this is a complete mix of driving.

[Richyvrlimited]

attym3 said:

So why are they so bad? It's only a 1.6, I get the same if not a bit better out of my 3.0 M3!

Mark

crap aero, very low tech low compression engine, short ratio gearing. and in your particular case, batch injection.

[Riknos]

Richyvrlimited said:

attym3 said:

So why are they so bad? It's only a 1.6, I get the same if not a bit better out of my 3.0 M3!

Mark

crap aero, very low tech low compression engine, short ratio gearing. and in your particular case, batch injection.

Yup, what he said.

Mine varies wildly dependant on how I drive.

My last few fill ups:

[rovermorris999]

You're not trying hard enough. I once managed 18mpg with Mk2 1.8 over a tankful.

[300bhp/ton]

attym3 said:

So why are they so bad? It's only a 1.6, I get the same if not a bit better out of my 3.0 M3!

Mark

Engine not built or designed for economy at all. I had a similar age 1.6 Nissan coupe. While you could goad it to over mpg, it's modal average was more like 30-32mpg.

Short gearing, revvy nature, probably enthusiastic driving.

In short, small engines can be quite ste in mpg terms. Another example, my 1.6 Ghia Orion, H plate, so similar age again. Easily would average 28mpg and was not hard to see a regular 26mpg from it.

[skinny]

Richyvrlimited said:

crap aero, very low tech low compression engine, short ratio gearing. and in your particular case, batch injection.

yep they do have low compression ratio - which is why a turbo makes sense, the whole world is going downsize boosted these days for efficiency!! they are also going downspeeded but apart from the rare 3.6 ratio diff there's not a lot you can about that.

and as above, a very simple ecu that was programmed 20 years ago.

i'm turbo'd and megasquirted (slightly more modern ECU - still batch injection tho) and i'll typically get 30 - 33 mpg from my bbr on mixed driving (commuting and weekends)

Edited by skinny on Tuesday 12th July 11:16

[abarber]

That's not bad tbh for a low tech old MX5. I got about that from my M2 1.8. Averaging at least 10% better on fuel now with a 260bhp 330i!