General Premium Fuel - to buy or not to buy

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General Premium Fuel - to buy or not to buy

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Hey Guys, wanted to start a thread for all fiat cars,( but had to choose a category so went with grande punto). But wanted to get a discussion going on people's feelings and experiences to Premium Fuel (High RON octane fuel) . So if interested state Car model you own and then input what you have to say.

I'll get ball rolling.

Grande Punto Sporting 1.4 T-JET 2009: Not tried it yet as I'm cheap and just recently learned about its (potential) benefits. Surprised to see in my manual it's says to use a 95 Octane fuel - which is regular. Just would have thought turbo were to use higher. Love to hear from anyone with my car and their experiences, bu all welcome!
 
The octane index reflects the auto-ignition capability of a fuel; the highest the index, the more the fuel will resist to self-ignition due to temperature at end of compression stroke. The fuel is compared to a mix of iso-octane (not self-igniting) and n-heptane (very prone to self-ignition) which gives the numbers. Regular 95 is 95% octane and 5% heptane...
If the fuel auto-ignite, the expansion stroke goes off control since the timing is not repected anymore, the engine "knocks" and can potentially be destroyed !

That being said, an high-octane (98) fuel is NOT more powerfull than a regular (95) one !

For a given engine, the manufacturer will recommend using regular or premium fuel in accordance with the numerous measures and tests they perform during engineering. Unless the engine is modified, there is absolutely no need nor benefit to use higher octane fuel, any "improvement" would be purely subjective...

This should not refrain You to participate at Emersson's project though !!

BRs, Bernie

If someone here helped You understand, or better, fix your issue, hit the thanks icon @ bottom right corner, it's free and makes us feel helpy ;-)
 
Yes

Plus

Cars fitted with knock sensors will detect the beginning of the petrol to self ignite ( also called detonation or pinking or knocking ) the knock sensor sends a signal to the ECU , the ECU retards the ignition timing to protect the engine components.

When the beginning of knocking is no longer detected the ECU sets the ignition timing back to its normal settings. This system is fully automatic.

Retarding the ignition timing does result in a slight reduction of power and fuel economy.

So if manufacturer states your engine should be run on 98(or any higher number petrol) but you can use 95 with a slight loss of power and economy , you now know why.
 
Thanks to Jack and Berne as the two statements are what you hear and find out from professionals etc
So read them if you want to know hard facts of fuel usage. But we know it's one of those Myth buster type discussions, so still share , as I know couple people who manuals says use regular but they tried premium and they feel car is more.powerful and less noise and vice versa. So I'm not advocating to do it or not do it, just trying to get a good discussion from people who have done it and see where takes us
 
Thanks to Jack and Berne as the two statements are what you hear and find out from professionals etc
So read them if you want to know hard facts of fuel usage. But we know it's one of those Myth buster type discussions, so still share , as I know couple people who manuals says use regular but they tried premium and they feel car is more.powerful and less noise and vice versa. So I'm not advocating to do it or not do it, just trying to get a good discussion from people who have done it and see where takes us
trying to spell correctly and have a stab at grammar and punctuation meant I forgot to add -
You can do no harm to your petrol engine by using a higher number petrol than manufacturer recommends. If you want to use 98 instead of 95 etc give it a go and see if you think it's worth the extra cost.
Do not use aviation petrol it has lead added and will make your O2 / lambda / fuel air and cat stop working.
 
trying to spell correctly and have a stab at grammar and punctuation meant I forgot to add -
You can do no harm to your petrol engine by using a higher number petrol than manufacturer recommends. If you want to use 98 instead of 95 etc give it a go and see if you think it's worth the extra cost.
Do not use aviation petrol it has lead added and will make your O2 / lambda / fuel air and cat stop working.
Lol don't worry my.punctuation no better Lol. But yeah I have heard about that lead based.fuel not to use. But I may give.couple tanks of premium ago just to see my own verdict on it all.
 
For the stock car i am sure it's more that ok.
But after you tune it.. and the power increase almost doubles... like in my case 120hp at flywheel to 194 at the wheels now... i am a bit scared to use the full power of the car with 95 fuel.

It should be able to run safely... with obvious power drops... BUT.. i would still use 98 in mine.

The difference in cost for me is not an issue, since i use LPG when under 4k rpm and under 0.5 bar boost, after that i set it to automatically switch over to petrol.

I am thinking of switching it to petrol at 3.5k rpm and 0.5bar boost...
 
For the stock car i am sure it's more that ok.
But after you tune it.. and the power increase almost doubles... like in my case 120hp at flywheel to 194 at the wheels now... i am a bit scared to use the full power of the car with 95 fuel.

It should be able to run safely... with obvious power drops... BUT.. i would still use 98 in mine.

The difference in cost for me is not an issue, since i use LPG when under 4k rpm and under 0.5 bar boost, after that i set it to automatically switch over to petrol.

I am thinking of switching it to petrol at 3.5k rpm and 0.5bar boost...

Hey aurick

So I'm taking from your post you have suped up you car abit and now your saying you would recommend using the higher octane premium Fuel?
 
Hey aurick

So I'm taking from your post you have suped up you car abit and now your saying you would recommend using the higher octane premium Fuel?

Yes!
But only now... not for a stock car, it will not hurt but is certainly not worth it.
 
Diesel side. 1.3 gp 90hp 6 speed. I always use premium diesel. I'm not gonna say it's more powerful more economical as they advertise but engine it's definitely more quite than regular diesel. With regular diesel i think there is a little more turbo lag with full throttle in all gears.
Cost its not an issue (1.27€ for premium, 1.18€ regular. Petrol regular 1.55€!.i live in Greece)
 
Diesel engines is a totally different world ! They NEED the self ignitiion effect !!

The difference between Premium and Regular diesel is just about what additives the refiner puts in his mixture, where some may explain the less noise produced ...

BRs, Bernie

If someone here helped You understand, or better, fix your issue, hit the thanks icon @ bottom right, it's free and make us feel helpy ;-)
 
Diesel engines is a totally different world ! They NEED the self ignitiion effect !!

The difference between Premium and Regular diesel is just about what additives the refiner puts in his mixture, where some may explain the less noise produced ...

BRs, Bernie

If someone here helped You understand, or better, fix your issue, hit the thanks icon @ bottom right, it's free and make us feel helpy ;-)

Ill add my two pence worth on fuel again.

Don't use supermarkets - they add addatives that cause harm and issues with your fuel lines, injectors and the engine itself - its not so bad on the older cars but newer cars i would stay away.

Also - if its Naturally Aspirated - stick to standard fuels, premium ones will see no difference whatsoever, i never felt any change in 1.2 stilo when i used shell optimax / v power nitro, i thought it felt smoother but that was it - however, i think that was all in my head!.

Since then, i have a newer Stilo - the 1.9 16v Multijet (150hp).
When I bought it - I put £30 of standard diesel in it (not supermarket diesel) and drove it home from Leintwardine to Bradford.

I noticed, under full load it was kicking out a bit of smoke, rolling coal as you would say - however, that's not as bad as it was when i was booting it back up the motorway in March.

Since March and getting the car home, i have only ever used Shell V Power Nitro, it does seem a little quieter now and feels much smoother, it also runs much better when first starting up cold, it still kicks out a bit of coal when booting it but not as much as before.

All in All, i will stick to the premium diesel as I do noticed slightly better MPG, throttle response and a much smoother cold running engine, and that is all coupled with "Check glow plugs" warning when starting up cold, i think one of them is dead, i'm ready to buy 4 new ones but am **** scared about the removal of them - they look easy enough to get at, but don't want to snap them - have heard horror stories that they snap and its very common
 
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There are numerous similar threads on this subject, usually with arguments on both sides and no definite conclusion.

Compare the economy gains against the extra cost. What little gain you may make in better economy will be more than lost in the extra expense. Vehicle manufacturers will design their cars for standard grade fuel. You will gain little by using the higher grade, apart from a bigger hole in your wallet. Unless you have a highly tuned engine that needs it.
 
100% with Nigel ! There are so many other ways to save on fuel...

- check and adjust tyre pressure
- avoid driving with open window(s)
- use AC sparingly
- be gentle with the right pedal
- remove roof top / bar when not used
- plan your trip in advance
- fill-in at a gas station on your way back/to work
- fill half the tank, preferably early in the morning
- remove all un-necessary crap from the hatch
- look ahead of trafic so you can anticipate
- etc. etc.

BRs, Bernie
 
Some great responses on here and a lot for people to take away. My view is cannot comment has have not really tried. I am not really fussed 8f premium Fuel saves me more fuel ( not saying I'm Mr money bags cz I'm as cheap as they get lol) but I would defiantly change over if petrol users of a Corsa D SXI felt they noticed a healthier engine, smoother ride and feel. So I may give it a few takes as manual does says it's possible and post my results - try do some videos with it possibly :)
 
When I had a Tjet I used super unleaded all the time. Whether it made a difference I don't know but I felt better. That was enough for me.

I did use it on the autobahn at times so it was been used fully, shall we say.
 
When I had a Tjet I used super unleaded all the time. Whether it made a difference I don't know but I felt better. That was enough for me.

I did use it on the autobahn at times so it was been used fully, shall we say.

Spot on, I can recognise this. Same with engine oil, some will stick with their chosen magic formula making them feel better within themselves. This is a common human trait.
 
Apart from older performance cars that were designed to run four star (and had hardened valve seats) the only car I've had that benefited from super unleaded was an Audi S4 (2.7 V6 twin turbo) and with that you either had to run a few tanks through or reset the "learnt" parameters via OBDII (Vag-Com, Oh, we are so lucky to have Multiecuscan an AlfaOBD) to see the difference. Even then it was marginal and I tended to only use it if I knew I was going for a long hard drive. For overseas readers, note that UK octane ratings are different (higher for same knock rating) than the USA.

Robert G8RPI.
 
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