[jsanket9578]

Has anyone had experience of filling XP95 fuel in a Duke 250? I am eager to try out on my BS4 bike that I recently picked up pre-owned.

[PratikPatel]

Originally Posted by jsanket9578

Has anyone had experience of filling XP95 fuel in a Duke 250? I am eager to try out on my BS4 bike that I recently picked up pre-owned.

Seriously, don’t waste your money. You not going to get anything substantial out of using a higher octane on a stock Duke 250. The bike has been tuned for regular octane and using a higher octane fuel is just burning money without any gains.

[yaleen]

We have a Grand i10 AT which has a TC. Felt that the acceleration and drive felt little smoother to me and my wife while driving with the XP95 fuel. Now I am not sure if this was a placebo effect as its feels like a minor improvement, but will try and fill xp95 any chance I get and see if there is improvement in FE as well.

Availability is sketchy, closest fuel station which has XP 95 is the one near SAP labs, ITPL in Bangalore, but it has not been available 2 out of the 3 time I visited.

[k491]

Originally Posted by jsanket9578

Has anyone had experience of filling XP95 fuel in a Duke 250? I am eager to try out on my BS4 bike that I recently picked up pre-owned.

I've rode a full tank of XP95 on my 2017 Dominar 400. The bike was lot more peppy and rev happy than any other brand fuel I have tried so far.
Before anyone says it's all in my mind, I recently got a full tank of regular BP petrol as there was some shortage of fuel in my area, the bike is not rev happy, there are a lot more vibrations than before .
I would say it's definitely worth the extra money.
HP power is a close second to XP95.

[Ritkon]

Saw this gem of a thread while browsing through Team-BHP.

https://www.team-bhp.com/forum/techn...rformance.html (How does high octane fuel improve performance?)

The thread is quite old and was last updated in 2011, when fuel prices were, let's just say affordable.

However, now that we are in an era when fuel prices are hotter than a combustion chamber, do you still pamper your beloved 2 or 4 wheeled buddy with the premium liquid? If so, is it just because of mental satisfaction or do you actually see some benefit out of it?

I use the XP95 on both my car (Grand i10 BS4) and bike (Yamaha FZS V3 BS6). The only benefit I see is reduced knocking when driving at a higher gear than usual. Added to that is the fact that it is supposed to keep the engine cleaner. No significant benefits noticed in fuel efficiency (actually it's a bit worse), NVH or even emission tests (yes I tried). I don't think it is worth the premium, but have become a slave to the habit and just cannot go back to the usual petrol.

1. What do other fellow BHPians think?
2. Is it worth the price difference?
3. Have you noticed any noticeable benefit?
4. Do you care about it at all?

[Jeroen]

Well, we really have a different thread for this. But from aan engineering point of view what is relevant is the octane number your engine was designed for.

That is mentioned in the owner manual. The Internet might tell you differently, but they won’t refund you the difference in price!

The octane number is directly related to the compression ratio of your engine. That is fixed.
If it was designed for 95, putting 98 in is not going to much if anything. The other way around is a problem.

Can you actually hear your engine knocking? Many modern engines have knock sensors that will advance/retard the ignition timing. Some engines can benefit a bit from a higher octane number, but really only if you rev high and hard.

I have never seen that in India. I don’t think I have ever seen any engine in any car in India go over 2000rpm. And the. Of course many cars are diesel too��.

I use premium high octane on all my old and classic cars here in Europe. The only reason is the premium brands such as Shell, BP and Esso still sell 98E5. And the actual ethanol content in these fuels is zero percent. Old cars and E10 don’t mix well, irrespective of octane number.
All 95 octane these days is E10
Jeroen

[greenhorn]

I owned a civic Si in the US, and the owners manual said the car needs at least 91 octane when regular was less. So i always tanked up on 91 or 93. Never filled regular gas so wouldn't know the difference

[vikred]

I drive a 2015 Toyota RAV4 (2.5L gasoline engine) in the US. The manufacturer recommends "Unleaded gasoline (Octane rating 87 or higher)" which is the regular gasoline here. I always used the 87 octane fuel ever since I started owning this vehicle, and never gone above that.

Anecdotally, I believe whatever fuel efficiency or performance you gain (IF you gain) over the recommended grade by using a more premium tier fuel is negated by the higher price of the fuel. Example: gaining 5% efficiency by paying 10% more.

[Shreyas_H]

I drive a Polo 1L TSI. I have regularly been putting in 95 octane petrol - while the VW sales guy said normal should be fine, the fuel flap says use 95 octane petrol!

I do see a slight difference in engine smoothness/noise levels. Not really sure if it impacts mileage but people say it does improve it.

Given the already super high petrol prices, a 4.5 to 5 rupee premium for XP95 is fine for me!

[Ritkon]

Originally Posted by Jeroen

Can you actually hear your engine knocking? Many modern engines have knock sensors that will advance/retard the ignition timing. Some engines can benefit a bit from a higher octane number, but really only if you rev high and hard. Jeroen

I like to experiment with my steeds a bit and since testing top end performance is a bit *cough* difficult in India, I try to test the bottom end. That involves testing the lowest speed possible in each gear, without stalling.

The effect is more pronounced in the bike than the car. In the Yamaha, I could shift smoothly to 5th at 30kmph on the regular petrol and at about 27kmph on the XP95. It is a very consistent result. Also, when the engine does knock, it is about 5 to 6 judders in regular and 2 to 3 in XP95.
In the Grand i10, I could shift to 4th at about 40kmph on regular and slightly above 35kmph on XP95. Tested it on 5th gear also, but the results were inconsistent. Here too, judders are about 50% lesser in the high RON petrol.

All speeds are speedo indicated, so actual speeds are a bit less. Of-course these are useless and unrealistic results, but are fun to do to test the effects of the supposed lower knocking tendencies of high RON petrol.

I intend to do some 0-60 acceleration tests too, but that involves waking early in the morning to find an empty stretch of road and thus have to wait for at least a decade .

[Jeroen]

Originally Posted by Ritkon

I like to experiment with my steeds a bit and since testing top end performance is a bit *cough* difficult in India, I try to test the bottom end. That involves testing the lowest speed possible in each gear, without stalling.

The effect is more pronounced in the bike than the car. In the Yamaha, I could shift smoothly to 5th at 30kmph on the regular petrol and at about 27kmph on the XP95. It is a very consistent result. Also, when the engine does knock, it is about 5 to 6 judders in regular and 2 to 3 in XP95.
In the Grand i10, I could shift to 4th at about 40kmph on regular and slightly above 35kmph on XP95. Tested it on 5th gear also, but the results were inconsistent. Here too, judders are about 50% lesser in the high RON petrol.

All speeds are speedo indicated, so actual speeds are a bit less. Of-course these are useless and unrealistic results, but are fun to do to test the effects of the supposed lower knocking tendencies of high RON petrol.

I intend to do some 0-60 acceleration tests too, but that involves waking early in the morning to find an empty stretch of road and thus have to wait for at least a decade .

You are lugging the engine, that is really not comparable to what is generally referred to engine knock. Lugging will put a lot of stress on various engine parts, way more than typical engine knock, so be careful with your experiments.
What you are doing is trying to run an engine outside of its normal operating envelop. All bets are off, and any result is possible. You can’t draw conclusions from it.

Engine knock is most pronounced under hard acceleration and or heavy continuous load. Also, and I don’t want to alarm you, your engine could be experiencing engine knock without you ever noticing/hearing it. Only way to tell is with various testing equipment hooked up to your engine.

Not to be to harsh, but your experiments are not really a measure of engine knock at all. And to be totally clear, you don’t need to worry about the supposed lower knock tendencies of high octane fuel. It has been well researched and tested for over decades in every industry using internal combustion engines.


Jeroen

[Turbanator]

Originally Posted by Jeroen

But from aan engineering point of view what is relevant is the octane number your engine was designed for.

I will differ a bit, most EU engines work based on the tune. Say a B58 BMW engine in India will have a different tune for low-quality fuel. So until we change that tune, not much can be achieved even with a higher octane fuel and similarly, no harm should be caused to such engines even by using regular fuel.

Originally Posted by Ritkon

I use the XP95 on both my car (Grand i10 BS4) and bike (Yamaha FZS V3 BS6). The only benefit I see is reduced knocking when driving at a higher gear than usual. Added to that is the fact that it is supposed to keep the engine cleaner. No significant benefits noticed in fuel efficiency

As I mentioned above, cars or motorcycles which are manufactured and delivered for higher octane will benefit the most. On others, it will be mostly a placebo.

[Jeroen]

Originally Posted by Turbanator

I will differ a bit, most EU engines work based on the tune. Say a B58 BMW engine in India will have a different tune for low-quality fuel. So until we change that tune, not much can be achieved even with a higher octane fuel and similarly, no harm should be caused to such engines even by using regular fuel.

It is not a matter of opinion. It’s laws of physics and engineering. Engine design, most notably the compression ratio determine what would be the most optimum Octane number. Some engine are designed, by using some clever tuning to be able to run on a a certain bandwith of Octane number.

Octane number, high or low, has nothing to do with the fuel quality. I.e. high octane fuel is not necessarily a better fuel than a low octane number fuel.

If your engine was designed to run on say Octane 89, putting Octane 98 in it, is not going to make a difference. The other way round is likely to cause problems, noticeably pre ignition and engine knock.

Any engine will run best at the Octane number it was designed for. If an engine was designed for a high Octane number fuel and you run it a lower Octane number you could actually damage it. Most modern engines can handle a certain band with by fiddling a bit with the tuning, but only up to a point. Modern car ECUs with a host of various sensors are able to handle, within a certain degree different Octane numbers. Probably 2-3 points?

Cars are set up for the prevailing Octane numbers in a market. That could actually be more than just a typical tune. It could involve different cylinder heads, injectors, knock sensor and such.

The fact remains, on an existing car, in an existing market, running it at a different octane number at best won’t do much, at worst might damage your engine.

Jeroen

[Turbanator]

Originally Posted by Jeroen

Some engine are designed, by using some clever tuning to be able to run on a a certain bandwith of Octane number.

This is exactly what I am trying to tell. By having a different tune, you can run on a lower octane/ bad fuel. Bad fuel cannot have a higher octane due to the impurities, I think it's a given.

As an example, BMW will add a S858- Low Compression Engine, which is essentially a tune, though the engine will be same as elsewhere. Have a look at this thread -

https://f30.bimmerpost.com/forums/sh....php?t=1714190

[Ritkon]

Originally Posted by Turbanator

As I mentioned above, cars or motorcycles which are manufactured and delivered for higher octane will benefit the most. On others, it will be mostly a placebo.

Originally Posted by Jeroen

You are lugging the engine, that is really not comparable to what is generally referred to engine knock. Lugging will put a lot of stress on various engine parts, way more than typical engine knock, so be careful with your experiments.
What you are doing is trying to run an engine outside of its normal operating envelop. All bets are off, and any result is possible. You can’t draw conclusions from it.

Engine knock is most pronounced under hard acceleration and or heavy continuous load. Also, and I don’t want to alarm you, your engine could be experiencing engine knock without you ever noticing/hearing it. Only way to tell is with various testing equipment hooked up to your engine.

Not to be to harsh, but your experiments are not really a measure of engine knock at all. And to be totally clear, you don’t need to worry about the supposed lower knock tendencies of high octane fuel. It has been well researched and tested for over decades in every industry using internal combustion engines.


Jeroen

Thank you both for your advice. I am not really serious with my experiments, but just try to make my office commute a bit more entertaining. May I ask two more questions?

1. Is there any proven record of the supposed engine cleaning properties of premium fuels? If yes, is it same for petrol and diesel?

2. Earlier IOC used to sell XP (mid-2000's maybe) and now they have rebranded it as XP95. While XP was problematic (we faced issues with our M800 back then), XP95 is much better. Is it because XP used additives to boost octane number while XP95 uses better refining method? Or is it just because engines have got better over time?

I cannot get any reliable data regarding these. Any thoughts based on your experiences?