Its got pilot sport 4’s on at the minute which should help
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Both need 98 fuel to output maximum power but can adapt to lower octane fuel (95). you can remap both cars with 95 but run it with 98 for better result, but it's better to optimize the ECU to a specific fuel for maximum power output.
Let us know how it goes and what figures you get, you cars basically stock rn right?
My point was throughout the multitude of tests done I've never seen conclusive proof that 98 RON makes much, if any difference in terms of power. I understand the basis of additives allowing for a cleaner engine which might help long term but that's about it.
Generally the reason to use a certain type of fuel in the past at least is knocking, uneven combustion can cause damage to your engine and I've seen some specific cars designed for 98 RON but in most cases even semi-performance cars (sub 400 HP) should run fine with no power loss on 95 RON. Why there needs to be a 98 RON map for a 250HP car is beyond me, on a rolling road a decent 1.8T stock car made to run on 95 can match that.
Of course there's always exceptions to these musings, like JLR 575HP 5.0L cars recommending 95RON and Toyota stating reduced power if 95 is used on their GR Yaris. However the latter makes some sense as it's a 3 pot..
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Most tsi engines make about 10 horsepower more on 99 than 95. Stock mine is 180 with 99 its 190hp done on dyno.
You need to understand knock advance and ignition timing turbo pressure etc to understand how an ecu adjust the map to sort fuel.
So not a lot of difference then and that could be influenced by atmospheric or circumstantial effects. I do understand it in part as I used to track cars, I've run E85 via a fuelflex with larger injectors etc. and I've remapped a few ECU's, upgraded turbo's and re-built engines.. Those certainly make a difference.
Ultimately I was just curious, with E10 now the norm I'd be tempted to use super unleaded anyway.
As in a quicker TSI engine or tinkering? I've ordered a Golf R MK8 (320HP) and I'll probably test it on both 95 / 98. As for modding cars, I just enjoy tinkering as I'm sure many others do. Not sure what my next project will be though, looked at a MK3 Leon 290 but the prices at the moment have been prohibitive.. Got my eye on the new Toyota GR86 as well, it would be a perfect platform for more power.
Anyway, I'm getting off topic here so apologies. I appreciate the debate and I'm not trying to be contrarian for the sake of it, it's interesting to hear different opinions / takes and knowledge on the subject matter.
The 95,98,99 number is the octane number which is the fuel's ability to resist knock/pre ignition - the higher the number the more resistant.
This means the engine 'can' produce more power with a higher octane fuel ONLY if it's tuning (timing/boost/AFR/CR etc) can be further optimised.
Some cars can 'take advantage' of this increased knock resistance and do produce measurably more power, Golf GTI being one.
If the engine is tuned with 95 - and unable to take advantage of higher octane fuel then it will NOT produce any more power.
Sort of, RON is the "research" octane number which denotes levels of resistance to premature burn. A higher RON generally (or ideally) requires greater compression and higher timing (plus a slurry of other factors to consider like chambers, coatings etc.) due to the slower flame speed (meaning it's harder to ignite). Forced induction can offset this to a degree but ideally you'd have a high compression ratio engine, when used with 98 RON which combusts at higher temps the engine won't (generally) burn prematurely before reaching TDC (top dead centre). In this setup with an ECU that can take advantage of it a higher RON can provide more power and fuel economy. Yes, I understand the test is "anti-knock" over in the US but there's a lot more to it as fuel alone doesn't determine the "knock on" effect..
However the other way round is different because if the fuel quality is lower with a higher compression ratio plus uneven combustion you'll encounter "pinging" which quickly translates into a popped piston. Most modern ECU's have anti-knock sensors and O2 feedback even if I wouldn't completely rely on them and manufacturers generally give a wide margin for error unless the engine is extremely high strung. Think Yaris GR which is 3 pot 1.6T running 260 something PS?
I've never worked on a TSI engine so it might take advantage of it but I quote myself:" I've never seen conclusive proof that 98 RON makes much, if any difference in terms of power". That's usually because the car will either be created to run on a specific octane and can't be mixed or won't make use, some Japanese imports didn't mix well with 98.. Also I've worked on BMW's, Ford's, Vauxhalls and a few others and it didn't make that much difference. When it did we weren't talking extravagant differences either..
Very interested in how this TSI works though after this thread.. What are we talking here? 10% / 20% or something like 3% that would be barely noticeable and could again be due to extraneous factors?
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I think that you won't notice the difference if you do not drag race some friend with similar cars. And if you care about fuel prices then definitely not worth it.
So in conclusion if you are not interested in maximizing the power output of your car, a simple box will add some extra boost that may satisfy your needs. No warranty void. If you like trying to catch some extra horses here and there, using higher octane fuel is a way (usually in top end rpm). There are also other ways combined that all together can make some significant change. It depends on your needs really. Do you need a 300hp Fwd leon to go at speed limit?
What has it been like on fuel ?? obviously not expecting it to be the same but hoping it wont be really bad if I get mine mapped
So i booked in for wednesday morning. Im going for the 95 ron map as i cant guarantee i will use 99 all the time. But running 99 will give me more power on the 95 map. But not the other way round. It has to be run on 99 all the time with the 99 map as the timings different. They also said the 95 map and low boost 99 map are running the same boost. Unfortuantly ive not got the dyno runs as it was the remap from the sale. So im gonna have to guess its going to be about 240bhp. Slightly more when using 99. Hope it will get 250 with the 99 and apr filter.
Shame about the dyno runs not being included. Enjoy your remap it will bring instant joy and happiness i guarantee it
. Post up your thought once youve driven it thanks.Interesting about 95 running same boost as 99 map just different timing table
cool. Awesome gti really know there ****.
So went awesome today and had stage 1 map done 95 ron map Had no rolling road included so just a pic on the car park im afraid.
Drove pretty sensible back to brum because of the bad weather today and was defiantly happy. Breaks traction on just accelerating had traction lights flashin and stuff which was breaking the power. Was really happy. When i got closer to home i came to a familar stretch of road and turned the ecs to sport and give it the full beans. Was actually shocked at how this thing took off. The boost was strong and really got to speed fast. I will have to spend abit more time driving it but it has definitely impressed me.
Drove pretty sensible back to brum because of the bad weather today and was defiantly happy. Breaks traction on just accelerating had traction lights flashin and stuff which was breaking the power. Was really happy. When i got closer to home i came to a familar stretch of road and turned the ecs to sport and give it the full beans. Was actually shocked at how this thing took off. The boost was strong and really got to speed fast. I will have to spend abit more time driving it but it has definitely impressed me.
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I run around 217kPa max MAP on standard tune on my 1.4TSI. That's roughly 16.8psi of boost. Measured through OBD MAP readout. Seems so low even though the 1.8 has more volume?
Happy days. Enjoy the 3rd and 4th gear my favourites. Some nice new tures to give you some traction and full tracking. My car handled so badly when bought tracking was miles out. Back end used to break traction like a citroen saxo in the wet. New tyres and 4 wheel alignment sorted that.
Yh the tyres are not tht old but its been soaking today. Im sure it will grip up better when its dry. All in all tho really happy with the apr map. Apr induction kit going on after christmas.
What tyres you got.
Should chuck some momentum 99 fuel in now gain even more , see if you feel a difference.
Pilot sport 4 tyres they real good in rain too. Proberly less than a 1000 miles on em. Only use my car on the weekend now as i use a van in the week. One of the reasons why i decided to go for the map in the end.
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