99 Momentum No Difference

[jackcramerr]

I filled in 99 momentum but didn't notice any difference in engine sound or response. Thought I will share this. I will see if I get better mpg.

[toffee_pie]

???

[scudney]

You probably won't not immediately either,I have used it for years and won't use the ordinary 95,converted my friend who has a golf V5 and his exhaust note used to have a popping sound,which after he started using the 99 has disappeared and he gets better mpg too.Then 5p a litre extra also works out cheaper than buying a bottle of additive

[jackcramerr]

So I have to go through a few refills ? Maybe engine ecu changes settings ? I have never used additives. Had been using 95 octane from tesco.

I am very stringent when it comes to performance. I have spent money on performance chips in the past and all lost. The only mod that made a difference I noticed was when I put a supercharger in some cheap car.

[scudney]

Lol what sort of performance gains are you after then,petrol,air filters etc only make a minimal difference to be honest.

[toffee_pie]

indeed, you cant 'chip' a IS250 in the first place. If you want performance you need a ISF.

I use shell Nitro fuel every time, is it for performance gain or more horses? No but it does keep the car running smooth and trouble free so that does it for me.

[jackcramerr]

I am not after performance at the moment. I often hear people saying high octane transformed the car. so I wanted to experience that. ...

I am now hoping I get better mpg. I didn't check the last one (wrote numbers down but didn't calculate ). But the one before that was 23.4mpg.

I haven't chipped is250, sorry. I have chipped land cruiser's. And the chipping unit was called steinbauer. paid 1000 pounds so or for two ecu modules.

I had tried the following on one of a car I used to own during teen years:

these didn't seem to make difference

Bigger Battery

Performance spark plugs, cables and ignition coil

Intake

these made slight difference but could been placebo

headers

exhaust

Head shave for increased compression

Bore increase for slightly bigger pistons

fuel increase (started to Make black smoke but no power increase)

This made difference :

Supercharger

Electronic fuel injection upgrade and dual stage fuel pump

intercooler

I stopped after that.

[johnatg]

Two things:

One benefit of 'super' fuels from the brand suppliers, especially Shell V-Power Nitro, is the fuel system cleaning additives, which keep the fuel lines and injectors clean. You don't get those with supermarket fuel. See here: http://www.honestjohn.co.uk/askhj/answer/28321/shell-v-power-and-tesco-momentum-99 and here: http://www.honestjohn.co.uk/askhj/answer/50993/is-supermarket-fuel-inferior-to-petrol-station-fuel-

Secondly, almost all modern engines are optimised for 98 (or higher) Octane fuel. They have knock sensors, which retard the timing if more than an acceptable proportion of firing events result in knock. That protects the engine but results in lower performance than technically possible. You get more knock events with lower octane fuel. But maybe IS250 ecus are adaptive enough to keep the timing retarded if the car is always filled with 95 and need time (eg several fill ups) to allow timing to advance to fully adapt to 98/99.

I always use Shell V-Power, or if I can't find it, Texaco 98. Most Shell stations in some parts of the UK seem to have been sold to Texaco. (I have an old Shell station POI database on my sat nav and I quite often find that a Shell station I'm aiming for has turned into a Texaco one)

jack is quite right about supercharging - that's why I have it on my MX-5! (But it must have V-Power or it pinks (knocks) like crazy!)

[Jamesf1]

indeed, you cant 'chip' a IS250 in the first place. If you want performance you need a ISF.

I use shell Nitro fuel every time, is it for performance gain or more horses? No but it does keep the car running smooth and trouble free so that does it for me.

Ditto.

[rayaans]

There are a few issues in this thread and a lot of misconceptions.

Firstly, different cars will act different using different fuels. An IS250 is designed to run on 95 RON fuel and using 99 RON wont make that much difference in all honesty.

Also, to make a difference, you'll need to run the fuel for a minimum of 5k miles.

Now here is where 99 RON does make a difference - carbon build up. The additived will clean the injectors out, especially on the direct injection WITHOUT port injection IS250. In that case, you will notice a performance difference after 3-5k miles as the engine will run better.

On cars without direct injection, they arent really worth the extra cost. Besides, Id be going to places like BP and Shell to get petrol instead of Tesco. Its almost like me prescribing you antibiotics for a viral infection - youd think the antibiotics did their job when your cold goes away naturally - placebo.

Its also worth realising that the majority of users go for standard unleaded which has a much faster usage rate. The fuel in the super unleaded tank is almost always "stale" as it doesnt get used by many people. A simple trick to try it out is to fill 2 jerry cans. 1 with standard and 1 with super unleaded. Stick it in a ride on lawnmower and you'll realise how much condensation is in them just by the smoke that comes out.

[Jamesf1]

There are a few issues in this thread and a lot of misconceptions.

Firstly, different cars will act different using different fuels. An IS250 is designed to run on 95 RON fuel and using 99 RON wont make that much difference in all honesty.

Also, to make a difference, you'll need to run the fuel for a minimum of 5k miles.

Now here is where 99 RON does make a difference - carbon build up. The additived will clean the injectors out, especially on the direct injection WITHOUT port injection IS250. In that case, you will notice a performance difference after 3-5k miles as the engine will run better.

On cars without direct injection, they arent really worth the extra cost. Besides, Id be going to places like BP and Shell to get petrol instead of Tesco. Its almost like me prescribing you antibiotics for a viral infection - youd think the antibiotics did their job when your cold goes away naturally - placebo.

Its also worth realising that the majority of users go for standard unleaded which has a much faster usage rate. The fuel in the super unleaded tank is almost always "stale" as it doesnt get used by many people. A simple trick to try it out is to fill 2 jerry cans. 1 with standard and 1 with super unleaded. Stick it in a ride on lawnmower and you'll realise how much condensation is in them just by the smoke that comes out.

As the engine is Japanese, and Japanese fuel is higher RON than Europes default 95 then Id of thought conceptually its designed with higher RON in mind anyway?...

Evo magazine tested Shell optimax some years ago. I'm generalising a bit from memory here but it went something like this:They used a standard non performance hatch back - such as a Fiesta or Clio 1.6 , a Civic Type R and a Porsche Boxster.

All 3 cars were at around 10k miles at the start, and were tested for fuel consumption, BHP and 0-60. All had been run on standard unleaded to that point. All 3 were then run exclusively on Optimax for 10k miles and retested. The standard hatchback showed very little difference, the Type R showed a definate improvement in power and 0-60 and the Boxster showed bigger imrovement than the Type R. The overall impression was - the bigger the more pwerful the engine the bigger the gains.

Personally I use Vpower for its cleaning properties. Any perfomance gains are fine by me but not my main objective. I have use normally unleaded and Optimax\Vpower back to back in my own Type R and the IS 250 and both have improved MPG by a small amount. It may be a placebo effect but the IS runs very smoothly on Vpower.

Having read a lot on this subject it appears that Momentum 99 lags behind Vpower in terms of the cleading\additives package..

Evo magazine also did a test of 95 vs super, using a Golf GTI. The results were:

BP 95

Max power 204bhp

Max torque 242lb ft

BP Ultimate

Max power 212bhp

Max torque 252lb ft

[johnatg]

Indeed - I said before that 'almost' all...modern engines..optimised for 98 - I'd go so far as to say that all modern Japanese engines are optimised for high octane fuel. (By modern I mean from about the early 2000s when VVT and more sophisticated ecus became generally adopted) That's not to say that they won't run perfectly happily on 95 - note that the handbooks (not just Lexus ones) say minimum 95 - that's because that's because that's the minimum RON that gives acceptable performance. Those ecus are clever and cope well.

Although you might see slight performance gains in raw power - max power and 0-60 times - the main performance benefit with high octane fuel is at low revs. Between 1K and 2K or so rpm is when an engine will knock if it's run on lower octane fuel. It's hard to check out on an auto IS250 because you can't hold a high gear - the thing just changes down. But on a manual if you use a large throttle opening at say 1K rpm in 5th or 6th the difference between 95 and 98 will become really apparent - 98 fuel burns more smoothly and the timing (ignition) is retarded less.

Now I'm not advocating that you drive like that (you shouldn't let an engine labour), but the fact is that the benefits, although maybe not perceptible in normal driving are there and are one reason why fuel consumption can be up to 10% better with 98 (as long as you don't use the raw performance gains!)

The real killer punch as far as IS250 and other direct injection engines (which is getting toward being a majority these days) is in carbon build up reduction (on the inlet valves) It's a real problem which hasn't been fully sorted by the manufacturers yet - Shell, BP and Texaco (but probably not supermarket) premium fuels certainly help to combat it.

[johnatg]

BTW - carbon build up on the inlet valves is a bit of a mystery and it's not entirely obvious where it comes from. The valves (on DI engines) should be operating in fresh air. But some burnt gases from the combustion chamber do reach the backs of the valves and of course there's oil - some will leak down past the valve stems.

So is it oil or fuel that causes the carbon? It's controversial - but it's best to change the oil much more frequently than the service interval recommendations (which are there to minimise fleet costs whilst being OK for the lifetime of fleet use) and use fuel with clean burn characteristics and cleaning additives.

[rayaans]

Japanese fuels may be higher RON but that doesn't mean anything.

Historically Hondas have always benefitted from higher octane.

However, Lexus main market is predominantly the US and they have crap fuel and don't have any issues

[johnatg]

"Historically Hondas have always benefitted (sic) from higher octane"

Absolutely - because they were pretty much first with VVT and 'smarter' ecus.

"the US and they have crap fuel"

Only partly true. First off, the USA and Canada use a different octane measurement to the most of the rest of the world. We use RON - Research Octane Number.

USA uses AKI (anti-knock index) also known as PON (Posted or Pump Octane Number) or RdON (Road Octane Number) - all the same thing, and the number is a mean of MON and RON. MON (Motor Octane Number) is measured under a more severe regime than RON - in the UK it is rarely encountered and then only in motorsport applications. It typically comes out at about 10 points less than RON for the same fuel. Therefore AKI etc ((RON+MON)/2) typically measures about 5 points less than RON for the same fuel.

So - there is an equivalence: 91 AKI = 95/96 RON and 93 AKI = 98 RON

Gas stations in the US usually sell 3 of the 4 grades typically available - they are Regular (87 AKI), mid-grade (89 AKI), Plus (91 AKI) and Premium (93 AKI) (although you can find variations on that theme - and different areas of the US have different common grades). In mountain areas Regular may be only 85 AKI as you can use lower grade (lower octane) fuel at altitude (for reasons I won't go in to). You are more likely to find Premium on the East coast.

Regular is intended for older engines and eg agricultural use (note - diesel only became usual for US farm tractors in 1970's)

If you consult the US Lexus fuel guide (http://drivers.lexus.com/t3Portal/document/om/OM53839U/pdf/sec_06-01.pdf) (page 4), you will see that they recommend minimum 91 (AKI) - 96 RON. Read on - to page 18:

Quote:

Premium unleaded gasoline with an octane rating of 91 (Research Octane Number 96) or higher required for optimum engine performance. If 91 octane cannot be obtained, you may use unleaded gasoline with an octane rating as low as 87 (Research Octane Number 91). Use of unleaded gasoline with an octane rating lower than 91 may result in engine knocking. Persistent

knocking can lead to engine damage and should be corrected by refueling with higher octane unleaded gasoline.

(end q)

And on to Page 19:

Quote:

n. Lexus recommends the use of gasoline containing detergent additives

Lexus recommends the use of gasoline that contains detergent additives to

avoid build-up of engine deposits.

All gasoline sold in the US contains detergent additives to clean and/or keep

clean intake systems.

n Lexus recommends the use of cleaner burning gasoline

Cleaner burning gasoline, including reformulated gasoline that contains oxygenates

such as ethanol or MTBE (Methyl Tertiary Butyl Ether) is available in many

areas.

Lexus recommends the use of cleaner burning gasoline and appropriately blended

reformulated gasoline. These types of gasoline provide excellent vehicle performance,

reduce vehicle emissions and improve air quality.

(end q)

So - no different to UK

But 'gasoline containing detergent additives' and 'cleaner burning gasoline' = V-Power (or BP Ultimate - very expensive) or Texaco Supreme 97 in my book.

And now: " and don't have any issues "

Absolutely not so. US Lexus forums are full of reports of carbon build up - much worse than here. And also many people asking if they should use Plus or Premium 'if the car has been run on regular'. Also Premium is often not available, especially in the mid west.

I suspect that many US IS250s are run on regular gas on a regular basis and consequently do suffer from carbon build up.

[Vintagesixtysix]

John - interesting and factual as always....... Thanks for taking the time to put that post together.

While I would love to believe that premium octane petrol gives me more efficient burn for better acceleration etc......I suspect from a lay mans point of view that it's the detergent I'm investing in for long term engine protection.

Just as an aside... Having driven many thousands of miles across the US you have to understand the mentality and culture of our cousins over the pond towards gasoline..... Politically there will only be small levers being pulled no matter what the latest environmental global agreement has been signed. I remember the street protests outside forecourts when it went over $2 a gallon..... About a quid back then!

You only have to see the huge billboards on the side of the highways getting all excited about 32mpg highway mileage in a latest model...... Probably a sore point over here at the moment ;) (VW etc)

V66

Sent from my iPad using Lexus OC

[jackcramerr]

OK. I have seen for now: 23.4mpg and 28.68mpg with Tesco unleaded. I have witnessed 30.05mpg with momentum 99. Filled it up one more time with 99. Then I will move to shell.

I have to admit the local shell never sees an y customers

[rayaans]

OK. I have seen for now: 23.4mpg and 28.68mpg with Tesco unleaded. I have witnessed 30.05mpg with momentum 99. Filled it up one more time with 99. Then I will move to shell.

I have to admit the local shell never sees an y customers

Doesnt really prove anything though.

Temperature, humidity, tyre pressures, driving style etc etc all play a factor.

The only way you can realistically measure whether it makes a difference is to stick the car on a dyno with identical tyre pressures, with the termperature and humidity being somewhat the same

[jackcramerr]

rayaans Yeah you are right. it's just fruitless exercise but I had promised to share some number and to end this thread. But I do not see it coming economical in terms of fuel cost.

[Gramera flash]

I used Shell V power religiously over a long period of time in my previous car (Honda civic type R , FN2) and I don't think it made any difference whatsoever apart from costing me more.

Personally I think if you think it does then it's just psychological,

Just my opinion

[is200 Newbie]

The Shell V power or the higher octanes are more expensive as they contain cleaning agents - factor that against buying the supermarket fuel and using an additive such as BG or Redex into the tank then it comes in around the same cost (maybe a little cheaper per fill depending on the additive you use)

I have used the Shell V power and over time it has removed an issue I had with carbon build-up within the engine - at least it has not come back since I started using it. There are arguments on instances to use it and it does good to the running of the engine.

I now use it in alternate fills with no issues.

[jackcramerr]

but then there are many tests by random folks on YouTube proving additives off the shelf don't do anything... so I wouldn't bother with additives of the shelf...

[is200 Newbie]

I agree - there are loads of articles on the web for additives - not all are for increasing performance though as quite a few have specific applications - I would be more interested in finding a good one that meets the needs of the engine as I would imagine there are a lot out there that are not suitable.

I would look to the states on this as there has been a big issue over there with issues on carbon build-up of the engines running on lower ron values than our supermarket fuels - I would tend to err on the side of recommendations from users over there having used the additives with good results. Depends what you want from them I guess.

[Ishaq]

I had my car Engine Carbon Cleaned by a 30 minute service were Hydrogen gets pumped through the air inlet. I have done this service June 2014 and August 2015 - My car drives like a dream, sometimes when I am stationary it feels like I have stalled. I have even had comments from some people why my car is so silent - Is it hybrid...LOL Anyone interested then they come to you if you are in or around London, they might do outside of M25 aswell..Let me know.

I now use Shell Nitro at every fill due to this being my local - sometimes they have massive ques so I use Momentum

[Linas.P]

On 11/2/2015 at 2:27 PM, Ishaq said:

I had my car Engine Carbon Cleaned by a 30 minute service were Hydrogen gets pumped through the air inlet. I have done this service June 2014 and August 2015 - My car drives like a dream, sometimes when I am stationary it feels like I have stalled.

I was planing to do this for a while. Can you recommend any specific Hydrogen decarb service? I have found quite many placed offering the same thing for £99, just thought if it is the same everywhere, or maybe it is possible to do it cheaper? Do they as well do emission test before/after or can it be added for additional price - thanks in advance.