Hi all,
Due to the increase of gas prices and me and probably other contemplating in switching to cheaper gas, I have a question if switching from 93 octane to maybe 91 or 89 octane will harm the engine of my xB? If I were to switch, would it be best to drain the gas first then fill it up with 'cheaper' gas? Thanks for any input.

 

Why are you using a higher octane in the first place? I thought xBs were spose to use regular unleaded.

 

It seems like my car runs better with higher octane and that is why I always put higher octane in my cars. I had a bad experience with another car of mine 'cruding' out when I went to 89 octane. Car stalled and high pinging in the engine and it felt like the car was huffing and puffing, etc. Since the box is like a year old, is it safe to switch now?

 

ive never had a car run badly on the 89 octane . ive never used the higher octane gases simply because they cost so much. if your owners manual doesnt call for anything but 89 then i see no reason to get the premiums.

think its just a myth that cars run better on the higher octane fuels. i think all that it boils down to is whether or not the manufacturer recomends it.

 

With an old car that is knocking and pinging, higher octane can help that problem. Carbon can build up in the combustion chamber over a long time (100,000 miles or so) and cause hot spots and detonation with low octane gas--essentially turning it into a diesel. Many cars have a knock sensor that retards the timing when detonation occurs (don't know if Scions do) so you won't hear the knocking.

Best bet is to follow the owners manual. And you can run a few tanks of gas with one octane and then the other, and figure out how many miles and how much money each one costs.

BTW, you don't have to drain the gas to switch--mix any ratio you want.

 

Thats funny i've been running 87 since day one. It's the reason i bought the car as a econobox. Theres no way i'm paying more money for higher octane when the engine can't make use of the octane. Plus higher octane=more carbon= more buildup. If I'm gonna use 94+ octane it'd better be on something turbocharged.

 

*Looks through owners manual. Finds part on gas needs.

The owners manual states that 87 grade fuel is all that is needed. If you have had bad times with 87, you have got it from a crappy station. I run 87 no problem, have nice & smooth power delivery etc... All 87+ fuel does for the xB, is make it more costly to run. I my self, in the past have had bad problems with higher rated fuels ie: all my cars where rated for 87, I tried 93 & got crappy gas milage because engine no like the stuff.

 

I run nothing but 87 octane in mine since day one, and it runs fine.

Mav

 

not really responding since i already did i just want to see if my profile updated the way i wanted it too LOL

thanks

 

in response to boxlver's sig. Is that 206 xb made by Peugeot??? LOL

 

If your car is crappy with 89 octane, find another brand gas. I don't know if you're using a cheaper brand. I use Chevron 89 all the time and never have any problems at all.

 

thats what we call the placebo effect. right up there with the butt dyno. its only seems better becaus you want it to be.

never use any higher octane than what the manual recommends unless you have extensive engine modification (ie turbo or SC)

 

^^^ what he said. There is no difference in the cleanliness of the gasoline from different octane ratings AT THE SAME STATION. If you buy 87 gas from chevron vs. 87 gas from "larry joe bill's gas and save mart center" there will be an obvious difference in the amount of detergents.

Go to www.toptiergas.com. Read and read more.

 

definately no need for 93. we run 91 on turbo cars out in cali. 87 is fine, but if u wanna dish out extra, then go for it

 

Thanks for the info all. I will be switching to 89 when I'm close to "E".

 

I am thinking of going the other way... If I'm spending $3.29 for a gallon of 87, the percentage difference between $3.29 and $3.49 isn't that much. Anyone else have similar thoughts?

 

^
Its always been that way, wont make me pay more =P

 

Someone correct me if im wrong, but this is how i understand it:
the octane rating determines the compression ratio that the gas can endure without detonating, since our little 4bangers dont have a high compression ratio, there's no need for higher octane, and the mileage will not be improved.
as far as gas quality, i have noticed a difference that i would find difficult to chalk up to placebo between the 'Top Tier' gas stations and the rest.
Current Top Tier stations are:
QuikTrip
Chevron
Conoco
Phillips
76
Shell
Entec Stations
MFA Oil Company

check out the top tier website at www.toptiergas.com

 

last i checked, 10.5 is fairly high for a car. my old focus svt was 10.5 and sipped on 91.

 

I know the price difference of about $.20 has always been there. My point is now that gas is as much as it is, the percent difference is not nearly as much as it was a few years ago. When gas was less than a dollar per gallon a few years ago, the percent difference would be about 20%, now that it is where it is, that premium has dropped to about 6% around here. For a 6% premium, I'd be more likely to buy a cleaner fuel (as some advertise.) I would not do the same for a 20% increase.