Running an E39 M5 on 95RON petrol
Discussion
BriC175 said:
Hi all,
Who runs their E39 M5 on 95RON? I presume it's perfectly safe to, given that it states in the owners handbook and under the fuel flap to run it on 95-98RON.
Me, ever since I've owned it which is now about 7 years. No problems. Averaging 24.2 mpg at the mo travelling about 40mile per day, with probably two foot down sessions up the gearbox per day.Who runs their E39 M5 on 95RON? I presume it's perfectly safe to, given that it states in the owners handbook and under the fuel flap to run it on 95-98RON.
It will run ok but i have found that i get virtually exactly to the mile the same miles/£s of petrol in my M3 by using shell v power than on regular 95 ron.It is also better for your engine and must also be better for performance.
So if you are thinking of using 95 octane to make the miles go further and try and save a few quid you could be surprised to find that might not necessarily be the case!
So if you are thinking of using 95 octane to make the miles go further and try and save a few quid you could be surprised to find that might not necessarily be the case!
95 Octane has a marginally higher calorific value so all other things being equal you would expect performance to be at least the same. If your engine has a knock sensor and a high CR then the ECU may be able to up the Ante on the ignition timing on 98Octane and gain a little here or there if the 95 Octane causes knock.
Dave
Dave
I'm not clued up enough to provide a cast iron rational for 98RON over the 95 stuff, but all I know is that after putting an emergency £20 worth of 95RON in my old M3 Evo (no Super available), the car ran like a bag of nails and I haven't repeated it since with any //M car (E34 notwithstanding).
For all the difference in price of a tank of 98 over 95, I can't understand why anyone would run a high performance car on the latter.
For all the difference in price of a tank of 98 over 95, I can't understand why anyone would run a high performance car on the latter.
Laird said:
I'm not clued up enough to provide a cast iron rational for 98RON over the 95 stuff, but all I know is that after putting an emergency £20 worth of 95RON in my old M3 Evo (no Super available), the car ran like a bag of nails and I haven't repeated it since with any //M car (E34 notwithstanding).
For all the difference in price of a tank of 98 over 95, I can't understand why anyone would run a high performance car on the latter.
My thoughts as well to be honest.For all the difference in price of a tank of 98 over 95, I can't understand why anyone would run a high performance car on the latter.
After getting stuck in the depths of Cornwall I used 95 (I think the first time she's had 95 ron in 7 years!)
The car DID NOT appreciate it. Marked difference in performance and economy.
There are two sorts of people I will never understand.....
The ones who convert M5's to LPG (should actually be against the law) and those who run performance cars on 95 ron. As rude as it sounds, if you can't afford super unleaded then you can't afford to run an M5 as it deserves.
I could go on.......(people putting the cheapest ebay suspension arms on)(budget tyres)etc etc
M5Tom said:
My thoughts as well to be honest.
After getting stuck in the depths of Cornwall I used 95 (I think the first time she's had 95 ron in 7 years!)
The car DID NOT appreciate it. Marked difference in performance and economy.
There are two sorts of people I will never understand.....
The ones who convert M5's to LPG (should actually be against the law) and those who run performance cars on 95 ron. As rude as it sounds, if you can't afford super unleaded then you can't afford to run an M5 as it deserves.
I could go on.......(people putting the cheapest ebay suspension arms on)(budget tyres)etc etc
My e46 M3 says 95/98 Ron inside the fuel cap. I used to put Super in, but started putting 95 in at Morrisons near my work, as there are no other garages without driving into town.After getting stuck in the depths of Cornwall I used 95 (I think the first time she's had 95 ron in 7 years!)
The car DID NOT appreciate it. Marked difference in performance and economy.
There are two sorts of people I will never understand.....
The ones who convert M5's to LPG (should actually be against the law) and those who run performance cars on 95 ron. As rude as it sounds, if you can't afford super unleaded then you can't afford to run an M5 as it deserves.
I could go on.......(people putting the cheapest ebay suspension arms on)(budget tyres)etc etc
It made no difference at all, not surprising really as BMW the people who built the car say to run it on a minimum of 95RON, which is normal unleaded.
As for the LPG comment, did you know that you can achieve more power with LPG than with super if you map the car to suit?
Edited by nottyash on Wednesday 7th September 22:28
Jesus some people are patronising. Of cause I can afford the petrol, and of cause I can afford maintenance. I just wanted peoples personal opinions. Life is about a compromise of things, not just instantly buying the most expensive thing because 'expensive stuff is better'. It's not always the case.
I know a lot of people tested high octane fuel on the Renault 5 GT Turbos during my time with the Renault Turbo Owners Club, and the summary was, it makes a Gnat's cock worth of difference to power. I also know it's not always the case though, as it depends on what the car is set up for. Given that BMW themselves state it can be run on 95RON fuel, it interested me as to whether people thought it made a difference.
So, any more relevant contributions, rather than lecturing me about the costs of running a performance car?
I know a lot of people tested high octane fuel on the Renault 5 GT Turbos during my time with the Renault Turbo Owners Club, and the summary was, it makes a Gnat's cock worth of difference to power. I also know it's not always the case though, as it depends on what the car is set up for. Given that BMW themselves state it can be run on 95RON fuel, it interested me as to whether people thought it made a difference.
So, any more relevant contributions, rather than lecturing me about the costs of running a performance car?
nottyash said:
did you know that you can achieve more power with LPG than with super if you map the car to suit?
Indeed you can! Higher Octane than fuel. Think it's about 105RON, but as common LPG conversions don't adjust ignition timing to suit, it rarely gets taken advantage of. Edited by BriC175 on Thursday 8th September 10:03
did the 95 vs 98 test on a long trip to the south of france (& back)
so repeatable conditions.
driving at a steady 80mph for a full tank of fuel at time the 98 improved consumption by 3-4 mpg (if i remember correctly) which more than pays for the incremtal price.
this was a few years ago in an Alfa v6, no reason to believe this has changed.
preference is Tesco 99 (it used to make the Tuscan pop & bang like a trooper
)
only 95 if I’m stuck or the price difference is ridiculous.
custard
so repeatable conditions.
driving at a steady 80mph for a full tank of fuel at time the 98 improved consumption by 3-4 mpg (if i remember correctly) which more than pays for the incremtal price.
this was a few years ago in an Alfa v6, no reason to believe this has changed.
preference is Tesco 99 (it used to make the Tuscan pop & bang like a trooper
)only 95 if I’m stuck or the price difference is ridiculous.
custard
BriC175 said:
Jesus some people are patronising. Of cause I can afford the petrol, and
So, any more relevant contributions, rather than lecturing me about the costs of running a performance car?
My name isn't Jesus and my post wasn't aimed personally at you Oliver. I know what it's like having performance cars at 21.......everyone is NOT patronising you, they're just jealous usually.So, any more relevant contributions, rather than lecturing me about the costs of running a performance car?
My very relevant contribution, similar to others....my E39 M5 does not run at it's peak when using 95 ron fuel.
It is proven that 'performance' fuels are better for engines in various ways. Not just power wise. Take a few engines apart and you'll see physically the difference.
I was simply stating I, Jesus the Lord, do not understand why anyone would put something in their very special S62 engine that they know could be better! Do they have any idea how much these engines cost to fix when they go wrong? It's like drinking the wine you get in the local off licence, 2 bottles for £4.50 or Glenns Vodka.........If you can afford £2100 on insurance mate then you can afford a bit of V Power every now and then!
Similar theory with the tyres etc. Someone buys a super saloon and then fits tyres to it that actually reduce the power it can put down, reduce grip and make you that little bit less able to stop on that day when you really really need to.
I suppose if you weren't planning on keeping the car then it doesn't matter. But regular oil changes with TWS/Edge and running her on V Power IS preventative maintainence to a small extent.
Not to mention the false economy of 95 ron as mentioned by the poster above.
Edited by M5Tom on Friday 9th September 03:45
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