gas octane differnce?

[STEvil]

here in europe we have a 95, 98 and a 100 octane gas.....mostly is used the 95 or 100 octane because it has high value....

Just so you know, the EU rates their fuel differently so ~95 in EU is the same as 87 in the states.

Same goes mileage wise. 40mpg EU is about 30mpg in the states.

Wish everyone could agree on a measurement standard

That said, I run 50/50 mix of premium (93) and 110 in my snowmobile

[V8SRSLO]

im very interested to know how mpg would change by country/location excluding terrain differences.

if my car got 50mpg on flat level ground @ an alt of 1500ft, anywhere in the world that is flat and level @ 1500ft my car would still get 50mpg it would not change because i was in Europe

also EU 95 would be closer to 91, EU 98 similar to 93 but there is no direct conversion, here in the US we take the average of research and motor octane( Ron + Mon/2) EU just uses the Ron(research octane number) which is always the higher number and without the data printout for any given batch of fuel there is no way to convert it. example Ron 95 Mon 87 the US would call this 91 octane now Ron 95 Mon 91 and US would call this 93 octane but both would be 95 in EU

[STEvil]

im very interested to know how mpg would change by country/location excluding terrain differences.

if my car got 50mpg on flat level ground @ an alt of 1500ft, anywhere in the world that is flat and level @ 1500ft my car would still get 50mpg it would not change because i was in Europe

also EU 95 would be closer to 91, EU 98 similar to 93 but there is no direct conversion, here in the US we take the average of research and motor octane( Ron + Mon/2) EU just uses the Ron(research octane number) which is always the higher number and without the data printout for any given batch of fuel there is no way to convert it. example Ron 95 Mon 87 the US would call this 91 octane now Ron 95 Mon 91 and US would call this 93 octane but both would be 95 in EU

It changes because they use a different measurement for a gallon.

[Tigerboy]

i have an 07 civic, i get better mileage on 87 vs 93, i felt when i switched to 93 i got a bit more pull, but after switching back to 87 i didnt feel that i lost the pull.. imo stick with what the manual recommends for your car, if they say you need 93 then use that, if not dont burn $$ into the oil companies. use that extra cash to go buy a tune then get 93

[Mtnbikecrazy55]

I have an 83 yamaha motorcycle, and it runs better on 91/93(whatever super premium is) than it does on 87.

However, this i think is due to the lack of ethanol therefore not gunking up the carbs. but thats just my idea. i have no knowledge on fuels on a technical level.

[STEvil]

Ethanol reduces power output of an engine, its a green gimmick basically.

Lower octane fuel actually produces more power than high octane fuel when used in the proper motor. The problem is that higher compression motors will detonate the fuel too early (read as faster) if its lower octane causing the engine to fail eventually. You can retard the timing to reduce this effect, or run higher octane fuel (which literally just burns slower to stop detonation).

Really if you're interested in more power and efficiency you can put a positive pressure air intake on your vehicle or a methanol/water spray. The water/methanol injection is a bit tricky though so its best to just try a cold air intake, though be sure you choose one that is effective as many are just gimmicks.

[purplesyrup]

i did a true test on this, I had an 18 mile highway drive to work and 18 back I used 87, and was getting about 15.5 mpg, then I tried 91, no joke my milage went up to around 20-22 mpg, I started doing the math, you might spend $5.00 on the fill up, but you emd up saving a whole lot more money because your tank runs out slower.

Let me explain reasons why there is such a difference

I worked at a liquor superstore that had a shell gas station on it, a federal law passes about a year ago, requiring that all grades of fuel except for super premium (91 octane+) were now required to have at least 10% ethonol in the gas. This caused an immediateimpact on fuel economy, making people that always use 87 octane have to fill up more frequently.

During this experiment I was doing (seriously same drive 7 days a week) was when the 10% requirement kicked in. I had been using 87 octane shell which was ethonol free, my MPG was at 18.5, as soon as that law passed and the fuel mix was changed my MPG dropped to 15.5, which is why i bumped back up to 91 octane. Where I saw even more of a gain.

Now all that being said, people that mow lawns and use things with smaller engines is where I started hearing complaints because the 10% ethonol was ruining peoples lawn equipment, its harsh on a small motor,

Hope this helps someone out.

My car suggests running 87, but the window sticker said 29 MPG highway, not 15.5 MPG, I do not excellerate fast, I drive normal, im never in any sort of hurry, so its got nothing to do with how I drive.

[98GCLimited]

I notice a little bit of a gain in mpg from using good quality gas with low ethanol content. The cheap gas with 10% ethanol is garbage. Pay the extra couple dollars per tank its worth it for the good stuff. Costs me $80 for a tank in my Jeep and maybe $3-5 extra for the good gas vs the cheap crap.

[STEvil]

Burn diesel, screw gas