ron 95 or ron 97

[astroboy]

So you mean if we are a regular 97, don't ever switch to 95...

It takes 1 to 2 week to get the timing to be optimal for a change in fuel grade despite the millions of calculation per second done in the ECU.

From 97 to 95, u will feel immediate lose of power, quieter engine, losing FC but after 1~2 weeks, FC will slowly improve and power will regain a bit but not like 97.

From 95 to 97, no immediate gain in power despite the more stable fuel as it takes time for ECU to slowly advance the timing from the optimal for 95 to adapt to 97. Again, 1~2 week to get it right.

.. so astroboy.. meaning the ECU will be confused if we always change fuel grades?..

If u keep switching fuel grade within 2 weeks, the ECU will be never get it right and as a result, u not only can't get the full potential of 97, your FC suffer big time too, with either fuel.

The key knowledge here is the 1~2 week rules of ECU adaptation to a change in fuel grade.

 

[cloudbuster]

Had been using Petronas for 10yrs+ since d petrol station was conveniently located near my residence. Swapped to Caltex RON95 six months ago and there has been no turning back ever since. I feel it gives a more responsive initial acceleration on my old 6 potter. However, there's no much difference in terms of performance or fuel consumption on the 4 cylinder E46.

 

[shiva73]

I used Ron95 on my e39 , car feel heavy and sluggish .

One day while on highway balik kampung , i noticed my fuel meter dropping to 'E' drasticly. I tot got big hole in my tank or what . I stopped the car and checked , nothing wrong and i called the mechanic . He said maybe the fuel pump KONG ready . So just continued the journey . When i m back in KL , i ran out of petrol just because i cant estimate the fuel left in tank . I have no choice , to get someone to buy me petrol from nearby kiosk .

Topped up and started the engine. Drove to the same kiosk , made the tank full with V power racing since other ron95 and ron97 pump was occupied.

The next morning when i start my car to visit the mechanic ( wana replace the fuel pump ) i found the fuel gauge is working . It lasted without any problem until i let go the car after 2 years.

Some said the vpower's quality made some magic on the fuel pump, but end of the day I saved at least 700rm for the fuel pump.

Now i only use ron97 and sometimes fill with vpower.

As for my misus's kelisa, i put ron95 lah .. takes off like a rocket : )

 

[ALBundy]

Its funny to see this discussion here. A good argument and make us think a bit. To be honest, all of them are the same within 1.2% tolerance in terms of content. (between the brands). The integrity of the fuel depends on the logistic and storage of the fuel. The fuel will deteriorate and contaminated in storages and transfers. I know this as I am supplying the systems to them.

All our UDMs run perfectly on 95. Anything more is waste of $$. Unless you tune your car up to limit on the advance of your ignition, you will not experience much benefit by going 97. Infact if we have 92, i will run 92.

For that 25% more in fuel price to compare with, it is a no brainer. By the way, non of BMW engines will be harm by not using 97. Absolutely no harm at all.

I am saying all these for the benefit of all and not just picking something down from the air. I am trained and educated in this topic so i do know a few things when it comes to Petroleum Products, physical and chemical properties of it.

I hope this can let more people understand the myth about 95 and 97 and even Vpower.

Would be more than to answer any doubts on this matter.

We are paying lots of taxes for income and cars.. so why pay more? 25% for questionable improvement?

Cheers
Alan

There was study done before with regards to the Ron rating of specific brands and it's more than 1.2% difference. It could
be contamination like you suggested or perhaps more
Benzene was added by that oil company.

As for our BMWs the older engines with lower compression could probably run with Ron 92 or even 89. Not the newer engines with high compression and advanced engine timing. On the M3, the difference between Ron 95 and v power racing is very noticeable.

Is benzene expensive?

 

[Vroom325]

It takes 1 to 2 week to get the timing to be optimal for a change in fuel grade despite the millions of calculation per second done in the ECU.

From 97 to 95, u will feel immediate lose of power, quieter engine, losing FC but after 1~2 weeks, FC will slowly improve and power will regain a bit but not like 97.

From 95 to 97, no immediate gain in power despite the more stable fuel as it takes time for ECU to slowly advance the timing from the optimal for 95 to adapt to 97. Again, 1~2 week to get it right.

If u keep switching fuel grade within 2 weeks, the ECU will be never get it right and as a result, u not only can't get the full potential of 97, your FC suffer big time too, with either fuel.

The key knowledge here is the 1~2 week rules of ECU adaptation to a change in fuel grade.

AB, I agree with you. When I first swithed to 95 from 97, so frustrated, noisy, sluggish, have to step harder. After few weeks, it's better and quieter.(may be getting use to it also) Of course, I can still feel a bit of difference vs 97 but not too bad. With the money save, step harder loh. hehe....

 

[Vroom325]

Had been using Petronas for 10yrs+ since d petrol station was conveniently located near my residence. Swapped to Caltex RON95 six months ago and there has been no turning back ever since. I feel it gives a more responsive initial acceleration on my old 6 potter. However, there's no much difference in terms of performance or fuel consumption on the 4 cylinder E46.

Cloudbuster. Yea, I agree with you on the caltex 95. When I switched to from Shell 97 to 95, cannot lah... ExxonMobil is better, but I think I want to try one more time. Caltex gives me the best feel so far, but there isn't much Caltex near by my house... Haven't try BHP yet...

 

[JFT63]

I'm using BHP ron95 for my m52b25tu n its reasonably good for my bimmer city driving..rm50 for 200km..pTRONAS is the worst, got less than 190km..other brands are not that bad though

 

[Stanley Tan]

Well said!! But what about power? will there be any difference??

 

[rpmnut]

Any mechanical difference if we use ron 95 such as problems with start up in the morning etc? I am using ron 97 now but am afraid to change to ron95. I heard that BM can use as low as ron 92, is this true?

Most BMW's are optimized for RON 91 - RON 98 petrols. If you're not sure what your car is tuned for, check the fuel flap. The sticker on the back of the flap will tell you what's the minimum RON your car needs to run.

But do note - the lower the octane, the lower the power your engine will produce. Lower octane petrol has lower knock-resisting properties, so to counteract this, the engine ECU on knock-sensor equipped cars (all BMW engines have this), will retard ignition when it detects auto-ignition (heard as mild "knocking" or "pinging" noises from the engine when under load), resulting in some power loss in the interest of engine longevity.

 

[Hikaru]

When I was driving my previous Toyota, I switched from Ron 97 to Ron 95 and I found that stepping harder is not that fun. You lose the sense if the throttle response being very immediate.

So for now my e46 will only be drinking ron97.

 

[ALBundy]

Most BMW's are optimized for RON 91 - RON 98 petrols. If you're not sure what your car is tuned for, check the fuel flap. The sticker on the back of the flap will tell you what's the minimum RON your car needs to run.

But do note - the lower the octane, the lower the power your engine will produce. Lower octane petrol has lower knock-resisting properties, so to counteract this, the engine ECU on knock-sensor equipped cars (all BMW engines have this), will retard ignition when it detects auto-ignition (heard as mild "knocking" or "pinging" noises from the engine when under load), resulting in some power loss in the interest of engine longevity.

Lower octane does not necessarily means lower engine power.

It all depends on the engine design.

If it's a low compression engine (relatively speaking say for example the M52B28 which has a 10.2:1 compression), I doubt there is any difference, well I don't feel it for sure in my E34. As for my other car which has a 11.2:1 compression, the difference is very noticeable, more so with V Power Racing.

Cheers

 

[JFT63]

Well said!! But what about power? will there be any difference??

Obviously don't really feel the loss of power as B.Pahat traffic crawl everyday..pick up is more or less the same..my advice, give it a go..cheers

 

[B33mEr]

Caltex 97 Numero Uno for me ... BHP comes 2nd

I can't use RON95 simply because my mileage doesn't go as far as compared to RON97 and definitely i can feel a loss of power.

 

[Eggie86]

Caltex 97 Numero Uno for me ... BHP comes 2nd

I can't use RON95 simply because my mileage doesn't go as far as compared to RON97 and definitely i can feel a loss of power.

Subang area ada Caltex ah bro? Where ah? :4:

 

[Iylia H]

Subang area ada Caltex ah bro? Where ah? :4:

got lah bro... next to BHP... near the inti college roundabout in ss14... at the famous car wash place.

 

[B33mEr]

got lah bro... next to BHP... near the inti college roundabout in ss14... at the famous car wash place.

Yup or if you go straight on on the overhead bridge heading to Sunway there's one there and there one in USJ ( USJ 12 if i'm not mistaken ) that i go often too.

 

[jasonnn]

Yup or if you go straight on on the overhead bridge heading to Sunway there's one there and there one in USJ ( USJ 12 if i'm not mistaken ) that i go often too.

The Caltex in USJ is in USJ 16. Opposite the Restaurant Sri Melur, USJ 17. Can't be missed.

 

[B33mEr]

The Caltex in USJ is in USJ 16. Opposite the Restaurant Sri Melur, USJ 17. Can't be missed.

Ahh ... USJ 17 then hehehe

 

[EtEE]

Lower octane does not necessarily means lower engine power.

It all depends on the engine design.

If it's a low compression engine (relatively speaking say for example the M52B28 which has a 10.2:1 compression), I doubt there is any difference, well I don't feel it for sure in my E34. As for my other car which has a 11.2:1 compression, the difference is very noticeable, more so with V Power Racing.

Cheers

any idea wats the compression for e46, any power lost using ron95? So far m using ron97 and would like to try 95

 

[rpmnut]

Lower octane does not necessarily means lower engine power.

It all depends on the engine design.

If it's a low compression engine (relatively speaking say for example the M52B28 which has a 10.2:1 compression), I doubt there is any difference, well I don't feel it for sure in my E34. As for my other car which has a 11.2:1 compression, the difference is very noticeable, more so with V Power Racing.

Cheers

10.2:1 is actually quite a high compression ratio for an engine. For comparison purposes, the Golf GTi running the EA888 TSFI turbocharged engine, runs a compression ratio of just 10.3:1. As you can see, BMW's M52/M54 engines all run near-turbo levels of compression, between 10.2:1 (M52) and 10.5:1 (M54).

Mazda's SkyActivG engines hold the record for compression ratios though. They run a compression of 14.0:1 without the aid of a turbo.