Z4M - Running it on 95 ron instead of 97 ron.

[Hark]

Same straight 6 engine as the M3 (M54 is it?)

Book says ideally it should run on 97 Ron.

Previous owner ran it on 95 ron.

I've ran a few tanks of each and mpg and performance seems no better on 95 than tesco 99.

The previous car showed a noticeable diference.

Does anyone else on here with high powered NA cars use standard fuel?

[Great Pretender]

I'm baffled by this. If the book says to run it on 97, you run it on 97. These cars get very upset with standard fuel and 95 should only be used as a last resort.

Feed it what it asks for; any notion of saving a few pence here and there by opting for the cheap fuel is not the sort of attitude you should have to running an //M car I'm afraid. wky as it sounds.

[steelej]

I use standard 95 in my F430 and XKR but it says in the manual to do that, if it told me to use 97 i'd use 97.

John,

[Kong]

I would be very suprised if running it on 95 would do it any harm. Just think about the availability of super in some areas. Or think about the number of morons who are likely to buy them.

Very few production cars 'have' to run on super, the Evo FQ-400 being one of them.

I could of course be talking utter bks

[Great Pretender]

Kong said:

I would be very suprised if running it on 95 would do it any harm. Just think about the availability of super in some areas. Or think about the number of morons who are likely to buy them.

Very few production cars 'have' to run on super, the Evo FQ-400 being one of them.

I could of course be talking utter bks

Not 'harm' as such, but in my experience, no //M car I've owned (and there as been nine of them) has run right on 95 RON.

[MarkRSi]

I've never owned a turbo car, but do these (or high performance N/A's) absolutely *have* to run on 97+, or will they just produce less power on 95??

[steelej]

MarkRSi said:

I've never owned a turbo car, but do these (or high performance N/A's) absolutely *have* to run on 97+, or will they just produce less power on 95??

It all depends on what the car is setup for. High performance cars don't need to be setup to use 97, see my examples, 490bhp Ferrari and 420 bhp XKR both designed to run on 95, but if it told me in my manual to use 97 i'd use 97 as it's obviously been setup for that.

John.

[Kong]

Great Pretender said:

Kong said:

I would be very suprised if running it on 95 would do it any harm. Just think about the availability of super in some areas. Or think about the number of morons who are likely to buy them.

Very few production cars 'have' to run on super, the Evo FQ-400 being one of them.

I could of course be talking utter bks

Not 'harm' as such, but in my experience, no //M car I've owned (and there as been nine of them) has run right on 95 RON.

So you have run all 9 of your //M cars on 95?

I agree with what you are saying though, i only use 99 in my BMW and it isnt even an //M. But with regard to the OP i wouldnt be worried buying one used only on 95.

[Easty-5]

Running an engine on a lower RON fuel than it was setup to run on can cause harm. You're more likely to experience DET when running a lower RON fuel. There is a plenty scientific explanations out there if you search.

[Great Pretender]

Kong said:

Great Pretender said:

Kong said:

I would be very suprised if running it on 95 would do it any harm. Just think about the availability of super in some areas. Or think about the number of morons who are likely to buy them.

Very few production cars 'have' to run on super, the Evo FQ-400 being one of them.

I could of course be talking utter bks

Not 'harm' as such, but in my experience, no //M car I've owned (and there as been nine of them) has run right on 95 RON.

So you have run all 9 of your //M cars on 95?

I agree with what you are saying though, i only use 99 in my BMW and it isnt even an //M. But with regard to the OP i wouldnt be worried buying one used only on 95.

I would. If it's been run on cheap fuel, what else has been scrimped on?

And yes, most cars I've had have tasted a drop of 95 at one point or another where there wasn't any 97 available and none of them felt as perky as a result.

[martin mrt]

I ran my E46 M3 on 95 ron for a while as the local shell garage were out of V Power, and in all fairness i never noticed much of a difference if any, but for 99% of my ownership i ran it on purely V Power

[007 VXR]

A lot of ECUs take time to ajusted to diffrent fuel
but if the book says 97 for god sake use 97

also if the book says 95 but then you mod the engine run a higher ron

i only use 99 V power in mine

[roverspeed]

All modern cars will have knock sensors.

The Ecu will just retard ignition to compensate.

Very unlikely that you will lose noticable power, most likely you won't have just as sharp a throttle response.

[anonymous-user]

My car runs very poorly on 95 compared to 99. I know it shouldn't but it idles like a bd on anything less and sometimes won't start first time. The difference in cost between the 2 is negligable, I'd just use what it wants if I were you.

[Eggman]

I'm with roverspeed; I'd be surprised to find a modern car without a knock sensor.

[Egg Chaser]

roverspeed said:

All modern cars will have knock sensors.

The Ecu will just retard ignition to compensate.

This.

[BMWBen]

Egg Chaser said:

roverspeed said:

All modern cars will have knock sensors.

The Ecu will just retard ignition to compensate.

This.

Thirded.

Knock sensor takes care of it, and it won't have caused any problems.

[DJC]

Never noticed any difference in any car whether on 95 or 97 or 99.

[Daston]

BMWBen said:

Egg Chaser said:

roverspeed said:

All modern cars will have knock sensors.

The Ecu will just retard ignition to compensate.

This.

Thirded.

Knock sensor takes care of it, and it won't have caused any problems.

Yep shouldnt be an issue at all, my Tiv dosnt get V-power every fill

[mat205125]

My M3 with the same engine lives almost entirely on V-Power. When it must / does run on vanilla unleaded, it doesn't feel as responsive / eager / willing / smooth.

It is, however, impossible for me to pinpoint how much, if any, of this difference is tangible, and what proportion is entirely subjective.