New LF1 problems

[mckeann]

That sounds like a bit of a cop out.

[B12ANR]

I'm not amused either. I've contacted Lotus directly again today so there's more to come.

[les]

That sounds like a bit of a cop out.

Yup agree 110%, Toyota or indeed Rover engines should be able to run on any UK grade of petrol.

[robin]

That sounds like a bit of a cop out.

Yup agree 110%, Toyota or indeed Rover engines should be able to run on any UK grade of petrol.

On the Rover engine the ECU has no knock control and is mapped for 95RON. If you use 100RON or similar there is no change in mapping. The higher octane fuel burns more slowly (as I understand it); if this slower burning has any effect, it will be to increase emissions and reduce power (and possibly to heat the exhaust manifold and cat more).

On the super charged toyota engines you need to take into account the effects of the super charger, intercooler efficiency and 57 other factors to work out the optimum ignition point. If fuel was just one grade, that would make the problem easier; fuel of different grades just adds at least one additional variable to the equation; it possibly adds more than one variable (because different "high performance" fuels have different additives).

That's no excuse for it not working, but you can see why it might not!

Does the engine work with 95RON? I would be inclined to run it on that!

Cheers,
Robin

[anthonyyule]

Does the engine work with 95RON? I would be inclined to run it on that!

Cheers,
Robin

Yup - the car will run on 95RON with no problems. Where I live we struggle to get good high-RON petrol so both the old Evora S and the Exige V6 regularly ran on 95RON. As it was regular I have no real benchmark against which to base how much performance I lost - but both cars (and now the new 64' plate Evora S) ran without any problems.

Of course I would run 97, 98, 99 if it were more readily available - but having to make do certainly hasn't been to the detriment of the mechanical performance of the car(s)

[steve_weegie]

You're right to contact Lotus directly, as the type of fuel used shouldn't cause this degree of a misfire unless it was contaminated.

Howewver.... Different fuels do have different burn rates, generally dictated by the specific gravity of the fuel, where lighter fuels tend to burn faster. If the fuel used was burning too fast for the current ECU's ignition mapping, the ECU should detect this and "should" correct via a timing retard and (/or) mixture enrichment trim though. I mapped my Audi on Tesco 99 but it's pretty happy on the council 95 ron I have access to here in the north. Sure, there are correctable knock issues at high loads, but nothing remotely approaching a misfire.

I would be tempted to ask other LF1 owners if they've had problems, as well as to see what Lotus say

[Shug]

Shouldn't be an issue as Weegie says, but Lotus have form for really crap "that'll do" maps on hot special editions. Neat fuel pouring into the cylinders of the S160 (and random cam timing) or the hideous 190 remap on the original Exige/340R.

One would have hoped they'd have grown out of that by now, though...