mk1 MX-5 1.6 vs. 1.8 torque & fuel consumption.

[Sprite2]

Any radical differences between the two? Is the 1.8 much torquier? Does it guzzle loads more fuel.

Thanks for any thoughts you may have.

[mxdi]

Used to get 35mpg out of my 1.8 or 330 miles to a tank. A 1.6 I drove when I was test driving a possible purchase felt very slow, the 1.8 had that extra oomph I needed.

[greg_D]

mxdi said:

Used to get 35mpg out of my 1.8 or 330 miles to a tank. A 1.6 I drove when I was test driving a possible purchase felt very slow, the 1.8 had that extra oomph I needed.

I know i keep banging on about it, but my consumption (before the turbo) was consistently 210-215 miles to the tank on both my mk2 and mk2.5. I must drive like a complete knob!!!!!

greg

[anonymous-user]

WRT fuel consumption, EGO (lambda) sensors are commonly well past their best in the earlier cars. I was getting 300km per tank tops on my '91 1.6 until I replaced the knackered (one wire) EGO sensor with a new (4 wire) sensor. I can now get 400km if I don't go too silly.

Incidentally, the standard ECU goes open loop above 4000 revs which equates to around 75mph in top. If you constantly cruise on the motorway at 80mph+ then you'll be dumping gallons of fuel into the engine and get terrible consumption compared to cruising a little slower and keeping it below 4k and letting the EGO do it's thing.

[swansea v6]

i regularly get 350km to a tank full in my mk 1 1.6, tho i do fill up way before the red zone

[steve bowen]

I got worse fuel consumption on my 1.8 as an n/a than any other car I've ever owned. Biggest problem is the super low gearing in the roadster 4.3:1 diff, motorways you watch the petrol needle drop and the rev needle fly.

I'm very unconvinced the mk1's put on weight at all as they aged, I think its more dependant on what options are fitted. I took mine a late 1997 mk1 1.8 S-Spec Eunos to a VOSA weigh bridge and with a full to the brim tank of petrol, oil & washer fluid it came out as 960Kg, 500Kg over front axle, 460Kg over rear axle. Only 20kg according to the books heavier than the 1989 launch 1.6 mk1. My car has powersteering over the 1989 original, electric windows, apparently more bracing and a bigger engine, yet just 20Kg extra weight? I bet an early car with Powersteering, ABS, Air con would be heavier than my late 1.8 mk1 without.

[thegreatsoprendo]

Sprite2 said:

Any radical differences between the two? Is the 1.8 much torquier? Does it guzzle loads more fuel.

Thanks for any thoughts you may have.

Hmmm... All the replies so far seem to have missed thae vital point that it depends which 1.6 engine we're talking about - the pre 94 115bhp version or the 90bhp post 94 model. Although I haven't driven the later 1.6, I suspect the power deficit (90bhp v 130bhp) would be very noticable. On the earlier 115bhp model the difference is much less pronounced, although the 1.8 still feels the torquier and quicker car.

With regard to fuel consumption, no MX-5 is as good as it might be given it's relatively low weight and power, but I couldn't say for sure how the 3 engines compare against each other.