Best Fuel To Use Is200/300

[noby76]

Hi guys, I dont have the IS200/300 owners manual can anyone confirm the best fuel Lexus recommends to use for these engines? Mine is an IS300 (2JZ-GE supra engine without turbo) I normally use Shell standard 95 RON but am thinking of switching to Shell V Power 99RON. yes it will work out about 8p more per litre which works out about another £5 per tank so wont break the Bank.

My previous vehicle was a ford Cougar V6 and the owners manual stated '95 RON fuel. 98 or higher can be used but offers no significant advantage'. Which confirmed the cougar V6 engine was designed to run on 95RON. My mates Honda S2000's owners manual also states 95 RON but recommends 99 RON for full power advantage since the Honda engine runs a higher compression ratio and also has VTEC.

I already know the advantages of using a higher octane fuel 99RON but want to know what the Lexus Owners manual states as these Lexus engines are more advaced than my previous cougar V6 i.e they have VVT-i, higher compression ratio, direct ignition, 2 knock sensors.

any replies will be appreciated.

[Mr.Rudus]

i think its 97 ron as standard but they can run on any grade of fuel.

i always use shell v-power.

got the habit as i have been using it in previous high compression modified cars.

the 1g fe of mine is standard at the engine.

i have tried 95 ron fuel & the car seems to struggle on pick up & hills with reduced mpg.

yes it costs more but depends what you want out your engine.

i have tried every fuel out there & the best is shell unleaded or v-power.

tesco momentum 99 is also good but looses its punch if in the tank too long.

i would go 99 ron on the 2jz. best engine toyota ever made.

try the two & get back to us - its your call -

[noby76]

Thanks Mr.Rudus is 97 RON what it states in the manual or is this just a guess lol.. mine drives and picks up fine on shell 95 RON but want to know if 99 RON is whats recommended due to both 1G-FE and 2JZ's engines high compression ratio and VVT-i technology. and we all know Japanese engines are designed and capable of running higher RON due to Japan fuels exceeding over 100 RON.

I prefer Shell or Esso (Mobil) as i beleive these two oil companies know what thier doing when it comes to refining fuel (no disrespect to Tesco momentume users tho). Just want to know exactly whats stated in the IS200/300 owners manual. If Lexus have detuned both these engines not to map on higher RON fuel i'll stick with standard 95RON and keep my extra 5iver per tank when filling up :D . let me know

[fjcfarrar]

Supermarket & Branded/"Superfuels" all come from the same refineries and are produced to the same rigid specifications as far as RON ratings are concerned. "Superfuels" contain a range of additives & claim advantages CAN result form using them. Independent tests confirm this is true: some cars are marginally improved - and other cars are actually marginally made worse. The effects are usually so slight that specialist measuring equipment is needed to detect them in cars that are running properly in the first place.

The main thing to look for is a fuel source that sells large volumes so that there is no stagnation or loss of volatiles in the storage tanks also that these tanks are clean and actually contain only the fuel shown on the pump.

Generally, all fuels of the specified RON rating will provide very similar results in terms of performance and long-term wear - but if you find one works particularly well in your car; stick to that.

[noby76]

Hi fjcfarrar, am already aware super markets buy from the big oil companies (Shell, Mobil, Texaco, Total) but super market fuels will only be the standard minus the secret additives which the big companies add to thiers and it will be up to the Supermarket companies to source thier own additives for the base fuels they buy from the big oil companies. I am a loyal Shell & Esso (Mobil) user and have used these in all my previous cars... all i wanted to know was if Lexus engines are designed to re-map the ECU when a higher octane fuel is used. some car munfacturer engines can do this others cant. e.g. honda S2000 engine re-maps its self when a higher octane fuel is put in and since Honda engines a similar to Toyotas i.e. they both have variable valve timing, both run a higher compression ratio with knock sensors and use direct ignition. all i want is someone to quote me what is says in the owners manual. i.e 95, 97 or 99 RON.

[fjcfarrar]

Hi fjcfarrar, am already aware super markets buy from the big oil companies (Shell, Mobil, Texaco, Total) but super market fuels will only be the standard minus the secret additives which the big companies add to thiers and it will be up to the Supermarket companies to source thier own additives for the base fuels they buy from the big oil companies. I am a loyal Shell & Esso (Mobil) user and have used these in all my previous cars... all i wanted to know was if Lexus engines are designed to re-map the ECU when a higher octane fuel is used. some car munfacturer engines can do this others cant. e.g. honda S2000 engine re-maps its self when a higher octane fuel is put in and since Honda engines a similar to Toyotas i.e. they both have variable valve timing, both run a higher compression ratio with knock sensors and use direct ignition. all i want is someone to quote me what is says in the owners manual. i.e 95, 97 or 99 RON.

Sorry to have misunderstood your question: The Lexus ECU is designed to adapt itself to different RON ratings for fuel, but because of tolerances in the system cannot do this perfectly; so will find the best compromise lies somewhere near the centre of the stated range. And again, because of tolerances, some will lean towards the lower end for best results - and some to the higher end.

The only thing that I can state with any certainty is that my IS200 didn't care what petrol you put into it, nor does my ISF - but I have had cars where there was a noticeable difference.

No help at all to you really because it means a bit of suck it & see to find what best suits your IS300.

[kenfoxy]

I would agree. The IS200 seems blind to whatever fuel you put in it.

[normski2]

Always used 95 ron in my is200Sport/Nav and it was absolutely fine.

[noby76]

cool guys! will try V Power for about a month and see how she performs on that if its no different from 95 RON will save the extra 5iver and keep using 95 RON.

[noby76]

OK guys, so after 8 months since I started this thread, I have used 2 different brands and three different grades of fuel in my IS3.

First: Esso(Mobil) Energy Supreme 97RON

Found this fuel OK was between 139.9 - 144.9p per litre during my test. didnt burn as fast as Shell's V power and engine note in general wasnt that sporty was more quieter engine note . engine was slugish on colder morning starts and was kinda getting 2-3 mpg more from this fuel and didnt really notice any thing with regards to responsiveness but it is a good fuel all the same.

Second: Shell V Power 99RON

was between 142.9 - 147.9p per litre during the test. The engine prefered this fuel compared to Esso 97 and normall Shell Unleaded. My IS3 tends to be a bit dull to start in cold mornings even though I have changed spark Plugs and fitted new Toyota Battery but using this fuel, the car cranks up instantly without any slight hesitations regardless of how cold the weather is, consumption is similar to Esso when driving normally but put your foot down, fire all those 6 cylinders and you will pay for it. this fuel burns really quickly on heavy engine acceleration and you can actually hear the engine car picks up well from a light foot an the accelerator pedal.

time to see if this toned down Ferrari fuel does deliver power: OK so i had this fuel in when a dude in Civic Type R wanted a challenge now for a 2 litre 4 cylinder those Civics are very very quick mind they weigh around 300kg lesser than IS300's and have 200bhp. we started off from around 70mph activated my ECT PWR button flicked my drive mode to M and dropped my gears ratios from 5th to 3rd he was ahead about a cars length he floored his and i did the same by 90 i was near his bumper and passing with ease kept my foot down whilst changing up my gears and next thing i looked at my guage i was sitting at 147mph not sure if this burst of speed was down to the fuel or the mode i set the car to as i felt the car could go a bit further but backed out of it. Same thing with a petrol Audi 2.0TFSI similar performance (208bhp) to IS3 but again theat dude was out tourqed and out run by the IS300 on this fuel. so maybe Shell wasnt lying afterall but will still say its inconclusive as i wouldt know how the car would have performed in the same scenario if normall unleaded Shell or Esso 97 was used but it certainly gave it some top end grunt.

Third: Shell normal Unleaded 95RON(note shell says its actually 96RON at the pumps)

normally between 134.9 - 137.9 p per litre so its no more expensive than Supermarkets fuel and Iam currenlty running this fuel. car has gone back to being a bit sluggish to start in slightly colder mornings on this fuel compared to V Power which makes it simialr to Esso Supreme. now the weird thing is the engine has become more responsive than when I was on V power from lower to mid rev acceleration also sounds sporty when the revs are climbing which is similar to V power but different to Esso's quietness. doesnt burn as quickly as V power when the car is under heavy acceleration load and I seem to get roughly 5mpg more comapred to V power when doing roughly the same journey. but this result might be inconclusive as I have fitted an Apexi high flow perfomance panel filter, cleaned my MAF sensor and reset ECU the day before i started using this fuel so not sure if the responsive and mpg gain is down to that or the fuel.

Conclusion:

Each fuel was used continously for roughly 2 - 3months each time covering around 700 miles each month. All three fuels I found good and smooth running for the engine Esso Supreme did not give the engine that sporty buzz tho returned slight improvement in mpg but not a lot. Shell normal unleaded returned the best mpg improvement results on normall driving and seems to be the best responsive fuel from low to mid burst of acceleration(again not sure if its MAF cleaning, Panel filter and ECU reset). V power on the other hand was the most responsive fuel top end wise and engine loved it at colder early morning starts and although it was the worst fuel to burn quickly on hard acceleration, a lot of accelerator effort wasn't needed to get the car moving from a stop.

Winner:

The Winner for me would have to be Shell normal Unleaded for the fact that its roughly the same price as Supermarket fuels and cheaper than both Esso Supreme and Shell V power. the engine is responsive doesnt burn as quicky as V power on heavy acceleration and the car idles very quitely in traffic too. Some will say fuel is fuel but this test has shown me there are slight differences and variations in the brands and grades. but saying that will keep chucking in V power every now and again just for that top end grunt. :)

[istanbul05]

Excellent post John

[fil4362]

good post, have you took into account air temperature though? old air is more dense then warm air and give more bang for your buck without changing fuel, hence putting a bettre cold air intake and and intercooler on your car for better performance. The Lexus doesnt change its ecu setting dependant on fuel grade. theres nothing onthe car that measures fuel grade so it cant change itself as it doesnt know whats in the tank. The car itself can richen or weeken the mixture/fuel air ration, can and does do this but thats based on the exhaust gases not fuel in the tank. Infact if the car doesnt richen and weeken the ration the cat doesnt work properly.

The recent test i saw was tech based using a dino. The car ,if i remember correclty ran a k series rover engine 1800, (the same a the lotus elise) The car was at normal temp in all test. They fuel varied from tesco home brew to top priced fuels from all major companies. They even tried fuel addatives, adding them to all the fuels. There was no significant horse power gains on any of the fuels or addatives. There was a few recorded increases of 3/4 bhp on the dino readings. I doubt anyone on a daily comute would notice the diffrence.

Having said all that , my old turbo did seems to sound diffrent and have more power on optimax, but looking back it was so slight it could have just been a placibo effect.

[wicked677]

There is a common myth than supermarket fuel is somehow inferior to that of shell or bp. This is not the case, the fuel is from the same refinery and sometimes even off the same tanker. For the cost of Shell super duper I don't believe the extra cost is worth the better MPG. It's like redex, I think sometimes people convince themselves that it is much better. I have never used the expensive fuels and never had any problems with the car, I just accept that the car has poor MPG compared to it's German counterparts. As for better engine performance, I think it has been marketed very cleverly, unless you have a ferrari you aren't really going to notice that much difference if any.

[noby76]

As for better engine performance, I think it has been marketed very cleverly, unless you have a ferrari you aren't really going to notice that much difference if any.

Wrong....this is a fuel test done couple of years ago which gave both Golf GTI and Subaru improved power and Torque figures across the rev range.. OK so they are both turbo charged cars so can take more advantage of cylinder volumetric effieciency due to compression ratio almost doubling with help of the turbo. but dont forget volumetric efficincey can also be improved with variable valve timing which in Lexus's case the valves could open earlier before exhaust valves close allowing a bit more air into the engine during the intake stroke couple that with a high compression ratio and ignition timing being able to advance its firing parameters and more power could be produced so its not only designed for Ferrari's . e.g. why do you think Honda/Toyota could acheive Turbo level figures in thier Celica VVTLi, Type R's and S2000's without a Turbo charger whilst similar cars in thier class result to Turbo to make the same power?? all down to valve timing and lift allowing more air into the engine during very high rpms to achieve 100% or more volumetric effieciency to produce Turbo power. so there is definately a gain to be had if ones engine has intelligent ECU's, sport cams, valves and higher cylinder compression ratio to make this happen. note its not the high octane fuel which makes the power its the ability of the fuel being able to hold off longer without self igniting during the compression stroke which makes the bigger bang(power) and higher octane fuels could hold off a bit longer without self igniting when the piston is compression air/fuel mixture. but if ones engine is not designed to make use of this then using a premium fuel is waste of money just like the Clio in this test. even if huge bhp figures are not gained, the car could be a bit more responsive. but these high octane fuels come alive when the engine is under heavy load during higher rpms so if one does not subject thier cars to that most of the time then again will be a waste to use these fuels unless one wants to make use of thier engine cleaning additives.

[52LAZ]

fair point about fuels in earlier post about doing nothing to a is200, i have run with several fuels in mine and there is no differance, same with my corolla t sport, i could tell no differance in that either, i say just use the fuel you can afford, makes no differance to a 150 bhp car anywho, lexus are great cars, if ya want to go quick, buy some else

[wicked677]

Had a look at that video it was interesting, made in conjunction with Ferrari. An extra £5 per tank for 5BHP on a GOLF GTI, if you can afford it go for it. Will you see the benefits on our bumpy grindy roads, I doubt it. Racetrack, probably.

Am off to fill up the car now, you have tempted me to fill up with supreme - but I can just about afford £90 a week on fuel so will give it a miss!

[esp]

I have Run my IS on Tesco 99 since I bough it never a problem. I have always run my cars on Supermarket fuel since I passed my test back in 1996 and i have run Petrol and Diesel never had a problem.

[scudney]

Hi,same here I have always used momentum 99 in all my cars(including 2 is 200's sports) in the last 12 years and never had a problem,also my way of doing a bit for the environment hehe

[fil4362]

I recently put in a tank full of the shell "super" fuel what ever it is they call it. As you can tell from my previous post on this thread i dont see any value in the stuff and after a full tank of the stuff still dont.

[ChrisIS200SportTTE]

I recently put in a tank full of the shell "super" fuel what ever it is they call it. As you can tell from my previous post on this thread i dont see any value in the stuff and after a full tank of the stuff still dont.

Did your MPG improve? That's the only reason I use high octane.

My drive to work is mostly A and B roads and from normal 95 Unleaded I get about 300 miles a tank, from 97 or 99 I get close to 400, 388 from the last tank. So I think that's beneficial even if it is £1.44 a litre :)

[noby76]

I recently put in a tank full of the shell "super" fuel what ever it is they call it. As you can tell from my previous post on this thread i dont see any value in the stuff and after a full tank of the stuff still dont.

high octane fuels will not automatically slap like 20+bhp to the IS200 or an NA engine compared to say the Subaru/Mitsu evo Turbo but can wake things up a lil bit on NA engines running high compression ratios like keeping the torque curve more linear from very low to high rpms, car could be a bit more sharper to respond, high speed cruising will be a breeze with no stress to the engine etc.

I alternate between 95 and 99RON to be honest and I'm currently running the Shell 99 at the moment due to cleaning additives, it being better at cold/freezing early mornings startups for my engine compared to 95 and i can happilly sit at 120mph on a late nite motorway journey with no stress to the engine. only way to find out if an NA car has gained extra bhp from high octane is to stick it on a dyno but like i said it wont be much unless its running redicilous high compression ratios like 11:0.1, 11:5.1, 12:0.1 as found in mainly high revving Jap cars eg JDM honda integra type R has been mapped to run 100RON from its high revving 1.8litre engine run this car on the exact ocatne Honda intended and you can hit 62mph in 5.8secs and clock 150mph all from a little 1.8litre. all down to how and engine has been tuned by the manufacture and ECU spec... if one wants power, forget using high octane on smaller less revving engines and go for high revving cars, forced induction cars or bigger cc engines as thats where true horse power lies.

[fil4362]

I dont see how the octane rating being higher will give you more mpg, the only real way this would happen is if it gave more power and therefore you needed less pedal travel for the same power. more power at less revs therefore less revs needed and better fuel consumption. I didnt trip the clock on the super fuel as its roughly the same from tank to tank. The only diffrence in fuel consuption depends on my mood, and how i drive. I can get 400 miles on a tank full but this is so boring driving i also managed 300 on a tank full bottom line it doesnt matter how much it uses when its gone i need more ha ha.

Morrisons is my nearest petrol station so when the lights on i go there, if i am passing the shell station and have 1/4 of a tank or so left i will go there but as someone has already mentioned the Lexus just doesnt seem to make any diffrence what ever fuel i put in.

I dont dispute there is gains to be had with the super fuels but noticing it on the Lexus i havnt.

[kenfoxy]

Wouldn't claim a noticeable difference between 95 and 99 petrol. My nearest station is a Tesco and as I wouldn't use Tesco 95, because of historical bad fuel issues, I use the Momentum stuff instead. I know it is more expensive than, say, Shell but by the time I have taken extra travel to Shell and Clubcard points, Tesco wins.