Petrol 90 Octane Or 95 Octane ???

nahsor16 · November 17, 2007

hi guys...

i've always wondered if 90 octane or 95 would give more value for money... cos to think of it at present 90 octane is 117 rupees per litre. whereas 95 octane is only about 2% more at 120 per litre. my car is a '92 toyota AE100 with 5AFE which does 11km/l city on 90 octane. will 95 octane increase my gas mileage??? if so any idea how?

Ripper · November 26, 2007

IMHO... the 95 does have a "visible" edge over the 90...

Don't pump 95 for my car since i didn't notice any "significant" improvement over the 90 i pump every day...

But on 2 stroke motorbikes...the difference is rather obvious

I had a 89model NSR250 with me for a few days few years back and on 95 it reaches it's top speed much faster than on 90...

I've done a 160kmh according to the bike's speedo on baseline road and the 95 has got there faster....

Not sure how exactly it worked but that was a stupid little test we did with TZR

Still pump 95 for my XR250 No particular reason... just hoping it'll be "cleaner" for the engine

Sparky · November 27, 2007

I've generally found a slight increase in power when using 95 octane over 90. This is over a couple of years usage on a carburreted and then an EFI engine. I also generally notice a lot of pinging at moderate to high RPM on both engines with 95. No noticable difference in mileage. Given the increase in power and the smoother ride I always choose 95 when it's available.

harshansenadhir · November 28, 2007

in contrary my 406 lost power when I pumped octane 95. had less than 1/4 tank when I refueled with octane 95 and afterwards I felt a loss in pickup.. and sudden jerks when pedal to the metal its D8 with 1.8l engine.. reverted back to octane 90. any 406 owners using octane 95 happily ??

pissa · January 11, 2008

guys, sorry to open up an old tread...i have a slight query, the user manual of a brand new yaris, mentions to use unleaded petrol with an octane rating higher than 87, so technically the 90 octane on our petrol stations should suffice right? Or is it leaded? (as in not unleaded) is the 95 unleaded?

the folks at Toyota lanka insist that the vehicle should only be pumped 95! (they obviously are not paying for it.... )

your thoughts please....

The Don · January 11, 2008

pissa said:
guys, sorry to open up an old tread...i have a slight query, the user manual of a brand new yaris, mentions to use unleaded petrol with an octane rating higher than 87, so technically the 90 octane on our petrol stations should suffice right? Or is it leaded? (as in not unleaded) is the 95 unleaded?
the folks at Toyota lanka insist that the vehicle should only be pumped 95! (they obviously are not paying for it.... )

your thoughts please....

The petrol in Sri Lanka is technically unleaded and this includes 90 Octane petrol. According to the manual 90 Octane petrol is sufficient for your car.

Supra_Natural · January 11, 2008

harshansenadhir said:
in contrary my 406 lost power when I pumped octane 95. had less than 1/4 tank when I refueled with octane 95 and afterwards I felt a loss in pickup.. and sudden jerks when pedal to the metal its D8 with 1.8l engine.. reverted back to octane 90. any 406 owners using octane 95 happily ??

again adding to old thread here, but to answer Harshan's question.... We ran a D9 1.8 ltr 406 (Uk import) for around a year and a half, almost exclusively pumped 95 octane, and it was as smooth as you like.... on one or two occasions i did pump 90 octane to see if there was a difference and IMHO there WAS a certain drop in performance (though by no means catastrophic) when compared to 95 octane.

GTAm · January 11, 2008

I would just like to share this info with everyone. DIMOs sent fuel samples of 90 and 95 to Mercedes Germany for analysis after they found problems with the E class. Mercedes concluded that the 90 octane fuel was of much better quality than 95. They said that the 95 has lots of impurities. Further analysis by Dimos revealed that as 95 is purchased in v small quantities compared to 90 it is done from various difference sources, and quality varies massively.

In contrast 90 is bought in large volumes from very regular sources.

I use 95 with regular fuel system cleaners as my hand book specifies a minimum of 95 octane but recomends 98!

Supra_Natural · January 11, 2008

GTAm said:
I would just like to share this info with everyone. DIMOs sent fuel samples of 90 and 95 to Mercedes Germany for analysis after they found problems with the E class. Mercedes concluded that the 90 octane fuel was of much better quality than 95. They said that the 95 has lots of impurities. Further analysis by Dimos revealed that as 95 is purchased in v small quantities compared to 90 it is done from various difference sources, and quality varies massively.
In contrast 90 is bought in large volumes from very regular sources.

I use 95 with regular fuel system cleaners as my hand book specifies a minimum of 95 octane but recomends 98!

That's very interesting, thanks for sharing that GTam, this could probably explain why D*MO Recommended that we pump 90 octane instead of 95....

raveen · January 11, 2008

GTAm said:
I would just like to share this info with everyone. DIMOs sent fuel samples of 90 and 95 to Mercedes Germany for analysis after they found problems with the E class. Mercedes concluded that the 90 octane fuel was of much better quality than 95. They said that the 95 has lots of impurities. Further analysis by Dimos revealed that as 95 is purchased in v small quantities compared to 90 it is done from various difference sources, and quality varies massively.
In contrast 90 is bought in large volumes from very regular sources.

I use 95 with regular fuel system cleaners as my hand book specifies a minimum of 95 octane but recomends 98!

90 waz much better quality than 95!?! thats interesting thankz for sharing that info with us.

pax · January 22, 2008

Hi,

Do I need to do empty my fuel tank if I am changing my fuel from 90 to 95, I just want to give it a try and see if it gives me more milage...

Or DO I pump the 95 once the fuel light comes up ????, will it be an issue when my old 90 gets mixed up ???

Please advice.

Elvis_Pil · January 22, 2008

pax said:
Hi,
Do I need to do empty my fuel tank if I am changing my fuel from 90 to 95, I just want to give it a try and see if it gives me more milage...

Or DO I pump the 95 once the fuel light comes up ????, will it be an issue when my old 90 gets mixed up ???

Please advice.

The answer is 'No' to all your questions. Just fill up

maithri · January 22, 2008

Guys,

Most 1970 t0 early 80's cars were made for 95 octane upwards leaded petrol. Lead improved the octane rating as well as the lubricant capacity of the fuel so the engine Valves and the valve seats lasted longer and we ran higher compression engines producing higher power outputs. The modern fuels are un-leaded (no lead). They use Benzine and various other chemicals to improve the octane rating. They do not offer the same lubricating properties as leaded petrol so the valve seats and the valves themselves are made from tougher metals. The 90's cars have catalytic converters fitted to clean up the exhaust gasses. These will get contaminated with the lead in leaded petrol so leaded petrol was removed from the wider markets. As the octane rating came down the engine management systems became more sophisticated and used knock sensors to identify pre ignition and to retard the engine timing dynamically to reduce or eliminate detonation and pre ignition. Most cars built in the 90's will function well using 90 octane fuels. The higher 95 octane as well as the 97 octane un leaded fuels sold in the west add better performance at the extreme margins but are not really any cleaner for the engine or the enviorenment as benzine can cause cancer.

There is a another factor for us in the uk now, Bio ethanol! This is nearly 100 octane but not all cars can run on it as the fuel is corrosive to some fuel system components. Totally made from crops grown for the purpose these in the UK cost only around half the price for a liter of Petrol.-Cheaper-Cleaner-Greener-more powerful-If your car can run on it you are in luck! One of my friends who run a performance car garage plans to build his next racer to accept this fuel as he supports green thinking as well.-A winner all around!

Maithri.

Arc Angel · January 23, 2008

maithri said:
Guys,
Most 1970 t0 early 80's cars were made for 95 octane upwards leaded petrol. Lead improved the octane rating as well as the lubricant capacity of the fuel so the engine Valves and the valve seats lasted longer and we ran higher compression engines producing higher power outputs. The modern fuels are un-leaded (no lead). They use Benzine and various other chemicals to improve the octane rating. They do not offer the same lubricating properties as leaded petrol so the valve seats and the valves themselves are made from tougher metals. The 90's cars have catalytic converters fitted to clean up the exhaust gasses. These will get contaminated with the lead in leaded petrol so leaded petrol was removed from the wider markets. As the octane rating came down the engine management systems became more sophisticated and used knock sensors to identify pre ignition and to retard the engine timing dynamically to reduce or eliminate detonation and pre ignition. Most cars built in the 90's will function well using 90 octane fuels. The higher 95 octane as well as the 97 octane un leaded fuels sold in the west add better performance at the extreme margins but are not really any cleaner for the engine or the enviorenment as benzine can cause cancer.

There is a another factor for us in the uk now, Bio ethanol! This is nearly 100 octane but not all cars can run on it as the fuel is corrosive to some fuel system components. Totally made from crops grown for the purpose these in the UK cost only around half the price for a liter of Petrol.-Cheaper-Cleaner-Greener-more powerful-If your car can run on it you are in luck! One of my friends who run a performance car garage plans to build his next racer to accept this fuel as he supports green thinking as well.-A winner all around!

Maithri.

guess this will be the way to go in the future... With companies like koenigsegg opting for this fuel on thier new production ccxR.

pissa · January 23, 2008

maithri said:
Guys,
Most 1970 t0 early 80's cars were made for 95 octane upwards leaded petrol. Lead improved the octane rating as well as the lubricant capacity of the fuel so the engine Valves and the valve seats lasted longer and we ran higher compression engines producing higher power outputs. The modern fuels are un-leaded (no lead). They use Benzine and various other chemicals to improve the octane rating. They do not offer the same lubricating properties as leaded petrol so the valve seats and the valves themselves are made from tougher metals. The 90's cars have catalytic converters fitted to clean up the exhaust gasses. These will get contaminated with the lead in leaded petrol so leaded petrol was removed from the wider markets. As the octane rating came down the engine management systems became more sophisticated and used knock sensors to identify pre ignition and to retard the engine timing dynamically to reduce or eliminate detonation and pre ignition. Most cars built in the 90's will function well using 90 octane fuels. The higher 95 octane as well as the 97 octane un leaded fuels sold in the west add better performance at the extreme margins but are not really any cleaner for the engine or the enviorenment as benzine can cause cancer.

There is a another factor for us in the uk now, Bio ethanol! This is nearly 100 octane but not all cars can run on it as the fuel is corrosive to some fuel system components. Totally made from crops grown for the purpose these in the UK cost only around half the price for a liter of Petrol.-Cheaper-Cleaner-Greener-more powerful-If your car can run on it you are in luck! One of my friends who run a performance car garage plans to build his next racer to accept this fuel as he supports green thinking as well.-A winner all around!

Maithri.

very informative...thanks....I like the sound of bio-ethanol, :-) someone told me that the reason for the food price increase around the world was related to developed countries using their corn etc to develop fuel, and as such they've stopped giving out food for lower prices for the developing countries like they used to....