Škoda TSI octane requirements 95 or 98?

[backdoc]

In this weeks local "Free Press Leader". I'm sure that it will be syndicated in all their various publications.

Distinctive character

by Peter Barnwell

"This is a really good car, the right size. plenty of go, sporty handling and feel and, after a recent makeover, good-looking too.
Skoda's Octavia RS TSi, (the turbo-petrol model) is in a competitive section of the market but measured against direct competitors like the Mazda 6, Honda Accord EURO and new Subaru Liberty Sport. The Czech-made five¬door lift back blows them all into the weeds in more than outright performance.
It runs a two-litre, turbo-petrol four-cylinder we know and love from the previous VW Golf GTi and is good for 147kW/280Nm output. That translates into a 0-100km/h sprint in 7.3 seconds.
Response on the move is impressive, aided in the test car's case by an optional double clutch (DSG) transmission with steering wheel paddle change -a $2,300 option on the base price of $37.990.
Equipment levels are generous and include a premium audio system, sports seats, dual-zone climate control. auto wipers and headlights. auto dim rear view mirror, six airbags and stability control.
It handles the way a sports sedan should, offering a taut feel and minimal body roll through turns, strong brakes and quick steering. The smooth-running engine with a bit of a burble is a gem, with as much squirt as any normal person could need and returns 7.7 litres/100km into the bargain -on 95 octane fuel.
The Octavia RS feels nimble and safe to drive. The body is rock solid and practical with the liftback rear and split-folding rear seats.
It's a largish car providing seats for five, four in comfort. and a large load area.
The driver's cockpit is stylish and functional. Essentially, Skoda's Octavia RS TSi is a keener priced VW with its own distinctive character. Definitely worth a look."

You can currently view the story on the Free Press Leader site (http://free-press-leader.whereilive.com.au/) by clicking on the "Browse the entire paper online" link. This will of course only work this week until a new edition comes out.


Bit of a shame they neglected their research. It's the same engine as the new GTI, just the same power outputs of the old engine, albleit on 95RON instead of 98 & improved fuel efficiency.

[woofy]

I still don't get why some RS are seemingly set up to run 98, mine definitely has 98 in the door with 95 in brackets as a fallback.

[Antiplastix]

Mine has 95 on the fuel filler cap. But the local BP only sells 98 anyway.
:confused:

[backdoc]

I still don't get why some RS are seemingly set up to run 98, mine definitely has 98 in the door with 95 in brackets as a fallback.

is yours a pre-FL? I know the old GTI engine required 98, the new engine is 95, but plenty of people seem intent on running 98. I can't see the value in it myself if the engine was tuned for 95.

[TuNeS]

the difference in price between 95 and 98 is nothing. you buy a nice car with a performance motor.....fill it with 98.

[backdoc]

the difference in price between 95 and 98 is nothing. you buy a nice car with a performance motor.....fill it with 98.

I had a MkV R32 and it never went without 98. But that was the specification. If the engine was tuned to run on 95, why use 98? Does it give you that warm fuzzy feeling inside?

Find some evidence that shows it is going to give performance or economy benefits for thie particular engine, then I'll listen. I just believe it is marketing hype!

[Manaz]

I used to work with Peter Barnwell - Barnie knows his cars, it's good to see he's impressed with the Skoda!

[Manaz]

I had a MkV R32 and it never went without 98. But that was the specification. If the engine was tuned to run on 95, why use 98? Does it give you that warm fuzzy feeling inside?

Find some evidence that shows it is going to give performance or economy benefits for thie particular engine, then I'll listen. I just believe it is marketing hype!

Most modern cars have an ability to vary their tune dependant on the fuel quality (not directly, but rather by monitoring for knocking and adjusting timing to suit the quality of the fuel they're burning). So running RON98 fuel can indeed have a benefit.

[backdoc]

Most modern cars have an ability to vary their tune dependant on the fuel quality (not directly, but rather by monitoring for knocking and adjusting timing to suit the quality of the fuel they're burning). So running RON98 fuel can indeed have a benefit.

I guess the point of this is - what is the benefit going to be? Not the perceived benefit, not the marketing of these fuel companies, but the real world benefit?

How will it improve my driving experience, how will it protect my engine, how will it save me money etc etc

[dazag]

I had a MkV R32 and it never went without 98. But that was the specification. If the engine was tuned to run on 95, why use 98? Does it give you that warm fuzzy feeling inside?

Find some evidence that shows it is going to give performance or economy benefits for thie particular engine, then I'll listen. I just believe it is marketing hype!

OK, the hype behind higher octane fuels.
- Less prone to detonation ( if you run a performance Turbo motor or high compression motor, detonation is a really bad thing, so to protect against it, you need to run higher octane fuel)
- depending on the company, the higher octane fuel is generally better quality ( more consistent Octane rating ) and burns cleaner. which means less contaminants in the oil and less carbon build up.
- 98 rate fuels are generally have a higher density, which means more "bang" for your buck, that's why you get better fuel mileage. The car doesn't need as much fuel to burn to get the same amount of power.

Generally I'e found that BP have the purest form of 98 fuel (Ultimate), as it contains the least amount of benzines etc. Jump on the sites and check out the MSDS sheets for each fuel, it will give you density's and what it contains etc

Run what ya want people, it's your car, if you think the fuel companies are just hyping it up, then put what ya want in your car and be happy with your choice. If you run a Turbo'd or high compression motor and you run 91, or possibly some 95 rated fuels then you could be doing damage to your car with out even knowing. Yes I know cars have "anti'knock systems on them, and that's when you'll feel the power drop off to protect the engine...........but why buy a performance car to only have it run at 95% of it's efficiency/power??

My work car is a typical Ford Falcon, and it only see's 91 as it has a very stock motor, and due to that i dont get to see much benefit in performance or economy from slipping in 95 or 98, although it does run better on 98 ( drives smoother etc)

I'm looking forward to when BP bring out the BP Ultimate diesel with it's higher cetane rating. The Skoda RS TDI will be living on that stuff if it makes it to NSW servo's

[woofy]

Mine is pre FL, as are most on here, but others from the same year have 95 as the min. I've never found out why, as I found it said 98 in all my research before buying the car.

[Graybags]

Having a modified Dyno tuned turbo engine with knock monitor for the past 8 years I can tell you that it knocks with anything less than 98. We took our cars to Tassie a few years ago (WRX car Club) where they only had 95 and we had to add octane booster to stop even stock engines check engine light coming on with high engine load. Agree with the last caller for piece of mind and maximum performance why not the extra $ for 98?

[backdoc]

OK, the hype behind higher octane fuels.
- Less prone to detonation ( if you run a performance Turbo motor or high compression motor, detonation is a really bad thing, so to protect against it, you need to run higher octane fuel)
- depending on the company, the higher octane fuel is generally better quality ( more consistent Octane rating ) and burns cleaner. which means less contaminants in the oil and less carbon build up.
- 98 rate fuels are generally have a higher density, which means more "bang" for your buck, that's why you get better fuel mileage. The car doesn't need as much fuel to burn to get the same amount of power.

Generally I'e found that BP have the purest form of 98 fuel (Ultimate), as it contains the least amount of benzines etc. Jump on the sites and check out the MSDS sheets for each fuel, it will give you density's and what it contains etc

Run what ya want people, it's your car, if you think the fuel companies are just hyping it up, then put what ya want in your car and be happy with your choice. If you run a Turbo'd or high compression motor and you run 91, or possibly some 95 rated fuels then you could be doing damage to your car with out even knowing. Yes I know cars have "anti'knock systems on them, and that's when you'll feel the power drop off to protect the engine...........but why buy a performance car to only have it run at 95% of it's efficiency/power??

My work car is a typical Ford Falcon, and it only see's 91 as it has a very stock motor, and due to that i dont get to see much benefit in performance or economy from slipping in 95 or 98, although it does run better on 98 ( drives smoother etc)

I'm looking forward to when BP bring out the BP Ultimate diesel with it's higher cetane rating. The Skoda RS TDI will be living on that stuff if it makes it to NSW servo's

If the fuels were the same price, then yes, "bang for your buck" applies, but when you're paying more "buck" for your "bang", then I'm no expert, but that doesn't seem to make fiscal sense.

Like I said, happily put 98 in a car designed for it, just don't believe in putting 98 into a car designed to run on 95. But that's the beauty of a democratic society, you can use what you want!

[Antiplastix]

Out of interest,my 2008 Triumph Street Triple with filter mods,Arrow 3>1 and a Power Commander III with custom map ran basicly the same figures on 91 as it did on 98. I think you will find that post modern FI engines will adjust down for lower ron fuel but you dont gain anything by putting in a higher octane than it is tuned to run on. The higher the compression level of the engine the higher the octane needed for the motor, this gets confusing in force inducted motors as their static compression is differant to their pressurised compression.
:confused:

[dazag]

Backdoc - yep you're right, you do pay more for the extra bang, but I should have worded that a little differently though to get across what I was talking about.
And yes you are right, if you have a turbo'd skoda that is tuned and designed to run 95, then there is no need to run 98 if you leave it in Stock trim. But if you ever decide to tweak the settings (especially with turbo boost settings) then fuel requirements will change, purely to ensure the engine doesn't detonate.

Antiplastix - with the PCIII , Did you play with it when running the different fuels to get the best out of each?? What fuel/air ratio did you have set up through the rev range and did you play with the ignition timing at all??
If you didn't play with the set ups when running the different fuels then I'm not surprised that the figures didn't change (assuming you're talking about dyno runs??)

All I'm saying is that if you have a stock car that says to run on 95 then that's fine, but if you have a car that says to run on 98, then make sure you do because there is either a compression difference or a boost difference between the engines and if you run a lower octane fuel then you can risk doing damage to the motor - it might not cost you now, but give it time your engine could be up for a rather hefty repair bill.

I wont go into the new E85 fuels you can get in some places (or the Shell V-power R 100 octane ethanol boosted fuels) , but to say a mate who has a very tweaked up Nissan GTR has had his car re-tuned (only fuel mapping as E85 runs leaner) to run E85 and got more HP & torque at the wheels, but again he wasn't tuning for efficiency.

[K1W1]

Us diesel drivers don't have any of these problems. We just occasionally fill up and continue driving. :-)

[Antiplastix]

Us diesel drivers don't have any of these problems. We just occasionally fill up and continue driving. :-)

Bloody, tractor drivers !!!!!
:brutal:

[Graybags]

A bit off topic but if you have a diesel and want more power maybe this could
be the answer?http://www.youtube.com/watch?v=hy9vy0pduMA

[selurs]

Mine is pre FL, as are most on here, but others from the same year have 95 as the min. I've never found out why, as I found it said 98 in all my research before buying the car.

There was an official statement made back in August about the VW group switching to 95 RON minimum for almost all their cars. Oddly can't find anything on the VW or Skoda websites, but a search of the Aussie car news sites turned up these from themotorreport.com.au (http://www.themotorreport.com.au/40407/volkswagen-skoda-revise-fuel-recommendation-for-petrol-engines/) and caradvice.com.au (http://www.caradvice.com.au/38849/new-volkswagen-engines-revised-for-95-ron-unleaded/) among others.

Anyway, the gist of it is that everything outside of the R32/R36 and GTI are now deemed 95 RON compatible, and that includes all Škodas.

Hopefully that's helpful and not pointing out stuff you already know :banana:

[woofy]

Hmm that article about the fuel only relates to the 2010 Skodas, although the engine is the same....still weird that some earlier 2008 cars had 95 in the fuel door and others didn't. It seems to only apply to 2010 released models for VW as well.

[backdoc]

Hmm that article about the fuel only relates to the 2010 Skodas, although the engine is the same....still weird that some earlier 2008 cars had 95 in the fuel door and others didn't. It seems to only apply to 2010 released models for VW as well.

Engine is the same as what? The FL Octy has a different engine to pre-FL. Not helped by the fact they have exact same outputs - "It's still a turbocharged 2.0-litre, four-cylinder but it's three kilograms lighter than the old unit and delivers more power and better fuel economy." from Drive. Plus it is designed to run on 95, not 98!

[wombatoutofhell]

I probably have the oldest Octy RS here as mine is a pre release model first registered in August 2007. Inside the fuel door is specifies 95ROM. I do tend to run it on 98 though as not all places have 95 unless you use the Ethanol laced one which I dont trust.

[woofy]

Hmm I completely missed that. I assumed it was still the old engine as everyone was bagging how the new Gti was more powerful, guess they didn't want SKoda stealing the thunder first, but I wouldn't be surprised if they quietly up the power in the next year to match the Golf.

[K1W1]

I wonder is there is the beginnings of a trend back to lower octane requirements? I noticed that all the new model Mazda 3's are designed for 91.

[Antiplastix]

The Mazda 3s always were 91 Ron. The Mazda 6 however required premium.
:confused:

[gerhard]

There's something unique in this paradigm

"I am happy to pay twice the price of a cheap Jap car to get my Euro car, but I will doggedly insist on saving three pennies a week on buying the worst quality fuel it will seemingly run happily on, rather than just filling the damn thing with 98; and will doggedly invent all sorts of arguments to support my (wrong) hypothesis"

FFS just fill the VW turbo engines with 98 and enjoy life.

If you really can't stand stumping up for the 3c difference between 95 and 98, sell the bloody demon and buy a Corolla which runs on 91 (more often 88 grade than not)

[Graybags]

LMFAO nicely said!

[backdoc]

Hmm I completely missed that. I assumed it was still the old engine as everyone was bagging how the new Gti was more powerful, guess they didn't want SKoda stealing the thunder first, but I wouldn't be surprised if they quietly up the power in the next year to match the Golf.

It is 8kw more powerful in the GTI but it is the same "new" engine. The TSI

[backdoc]

There's something unique in this paradigm

"I am happy to pay twice the price of a cheap Jap car to get my Euro car, but I will doggedly insist on saving three pennies a week on buying the worst quality fuel it will seemingly run happily on, rather than just filling the damn thing with 98; and will doggedly invent all sorts of arguments to support my (wrong) hypothesis"

FFS just fill the VW turbo engines with 98 and enjoy life.

If you really can't stand stumping up for the 3c difference between 95 and 98, sell the bloody demon and buy a Corolla which runs on 91 (more often 88 grade than not)

This is the whole point. It is not about the money. I ran 98 in my R32 because that's what it required.

I just find it interesting that there appears to be a relatively unfounded "truth" that these cars designed to run on 95 will somehow magically operate better on 98. If we were worried about fuel costs I don't think any of us would be looking at "performance" engines in the first place.

[gerhard]

I just find it interesting that there appears to be a relatively unfounded "truth" that these cars designed to run on 95 will somehow magically operate better on 98.

But that's where you are wrong about VAG engines.

Many of the current performance cars have more than one effective fuel map, so when you put 95 in, you get the 95 map. When you put 98 in, you get the 98 map, which gives you more power, and better economy.

Some less sophisticated and older car ECUs will NOT have the memory capacity to store more than one map, and will therefore not run any better on 98 than on 91. My Jackaroo is like that - you can put the better stuff in, but the output is no different.

But the latest VAG engines which can run on our 95 WILL run better on our 98.

[K1W1]

I'll start by saying I'm a neutral diesel owner. Now what we appear to have are two camps.

Camp 1. I buy 98 therefore I know my car performs better (because I'm justifying the additional cost to myself if nothing else).

Camp 2. I buy 95 therefore I know that my car runs no better on 98 but I'm justifying how clever I am by saving money.

Can somebody, anybody actually produce scientifically credible evidence one way or the other on these claims? By that I don't mean the seat of the pants dyno nor do I mean one owners fuel economy stats based on several tanks of fuel.

Does anybody have any real hard evidence to resolve this?

[TuNeS]

I cant provide any hard evidence between 95 and 98 except that the price difference isn't a lot. I havnt paid attention to the exact price difference between 95 and 98, however lets assume its 10c per litre. So after a 50L fill you pay an extra $5.

The TSI and TFSI are performance motors and the cars they are in are worth $40k+. Fill it with decent fuel!

If you want cost savings, buy the diesel variant.

I dont mean to offend anybody. Just my opinion on the matter.

[backdoc]

But that's where you are wrong about VAG engines.

Many of the current performance cars have more than one effective fuel map, so when you put 95 in, you get the 95 map. When you put 98 in, you get the 98 map, which gives you more power, and better economy.

Some less sophisticated and older car ECUs will NOT have the memory capacity to store more than one map, and will therefore not run any better on 98 than on 91. My Jackaroo is like that - you can put the better stuff in, but the output is no different.

But the latest VAG engines which can run on our 95 WILL run better on our 98.

Excuse my ignorance, but are you saying the car has sensors which determine what fuel you are running to determine the fuel map?

Despite all this conversation/debate, I will most likely only use 98 myself out of guilt. I don't believe I will notice any perceivable difference, but I'd feel like I was violating my brand new baby if I used the 95.

I would love to see some dyno comparisons though.

[K1W1]

I cant provide any hard evidence between 95 and 98 except that the price difference isn't a lot. I havnt paid attention to the exact price difference between 95 and 98, however lets assume its 10c per litre. So after a 50L fill you pay an extra $5.

Once again I'm a diesel nut so it doesn't matter but $5 per fill would equate to well over $300 per year for me and that is a large part of one service.

If you spend your days largely driving at the speed limit or stuck idling in traffic (how many mpg are do doing when stationery?) is the extra for 98 really worth the cost?

[dazag]

Just for info, I'm an oil burner also running the 2.0 TDI in my RS. The reason I know a little about fuels is due to my dirt bike racing and being a mechanic for a mate who used to race in the Shell Advance Road racing series. There is some tricky engine/fuel set ups you can play with, but today the advanced engine ECU's do seem to have an Octane Sensing

Here is some area's you can have a look at for info
http://www.shell.com.au/home/content/aus/products_services/on_the_road/fuels/shell_vpower/tech_spec/
There is a couple of test video's on there, but i wasn;t able to get them to work ( might be my system?)
Also BP has some interesting info as well. Have a look at www.bp.com.au
There is a bunch of test videos on the BP site showing the difference between Ultimate and normal Unleaded. I dont think you'd get the same difference between 95 & 98 unless you are driving high performance/high compression engines and have the appropiate tune for the fuel.
Check this page out and there is a video clip at the bottom of the page the shows a dyno run done on a Mitzibishi EVO with normal & Ultimate unleaded
http://www.bp.com/sectiongenericarticle.do?categoryId=9015032&contentId=7028158

Kiwi, being an oil burner check out
http://www.bp.com/sectiongenericarticle.do?categoryId=9024404&contentId=7045297

Just to add, looking into it, the 98's not only have higher octane ratings but also have friction modifiers, rust/corrosion preventitves, and Engine cleaner additives added to the fuel,, where as the 95's seem to only have the engine cleaning additive. Also of note was the volotility of the fuels is changed to suit the seasons, similar to how diesel has a winter & normal variant.

[K1W1]

Kiwi, being an oil burner check out



Ta.
In the last 6 months or so I have been using BP diesel almost exclusively in the Land Rover and it's added 50-70km per tank to the range in my normal driving. It took a couple of tanks before I noticed any difference I guess it needed to clean out the remnants of the previous fuels.

[gregozedobe]

If it is Ultimate diesel that has cleaner additives, and they may have cleaned up your injectors a bit = better atomisation of fuel = improved economy.

[brad]

I had a MkV R32 and it never went without 98. But that was the specification. If the engine was tuned to run on 95, why use 98? Does it give you that warm fuzzy feeling inside?

Find some evidence that shows it is going to give performance or economy benefits for thie particular engine, then I'll listen. I just believe it is marketing hype!

My fuel usage spreadsheet shows economy improvements using 98 over 95 ron in my 1.8TSI. My bum-dyno tells me it has better low down torque on 98ron.

I'm a firm believer in using the lowest octane possible but 98ron is the go. My figures prove it to me - don't really care what others think.

Supposedly the original DOHC 2.5 Liberty was tuned for 91ron - what BS. It was tuned for tight-arse Aussies that won't pay for PULP - always went heaps better & with better economy on 98ron.

[brad]

Excuse my ignorance, but are you saying the car has sensors which determine what fuel you are running to determine the fuel map?

Despite all this conversation/debate, I will most likely only use 98 myself out of guilt. I don't believe I will notice any perceivable difference, but I'd feel like I was violating my brand new baby if I used the 95.

I would love to see some dyno comparisons though.

There aren't any sensors to detect the type of fuel but the ECU will attempt to increase boost , ignition timing or run a leaner mixture until det/preignition is sensed. Early det/pre-ignition is not noticeable to an unamplified ear.

All I can suggest is that you do what I did. Run 95ron for a significant period (2000-3000km) then run 98 ron under the same conditions for a similar period. In my case, my economy improved enough for it to be a worthwhile spend on the 98ron. Surprisingly, Shell V-Power gives the best results in the chain drive engine (for me)

KIWI: What more do you want besides accurate spreadsheets? (agree, bum dyno don't count)

Are you willing to pay for dyno time?

[K1W1]

KIWI: What more do you want besides accurate spreadsheets? (agree, bum dyno don't count)

To me it's of no real consequence I was just trying to see if anybody has real proof.
Accurate spreadsheets are fine for an individuals purposes and I applaud you for having the patience to complete them but they don't constitute proof because to have proof you need two identical vehicles (at least) running the same fuel in identical situations and then measuring the results. That's the sort of stuff that is done in labs or on test tracks and that's the sort of stuff I was wondering if anybody had.