Gasoline octane rating question

cap_ut · 11-30-2005, 12:40 PM

In the manual it states that one should use regular 87 octance gasoline. Where I live, Salt Lake City, UT, regular gasoline is 85 octane. Will this be a problem? Should I go with the 87?

narf · 11-30-2005, 12:46 PM

Quote:

Originally posted by cap_ut@Nov 30 2005, 10:40 AM
In the manual it states that one should use regular 87 octance gasoline. Where I live, Salt Lake City, UT, regular gasoline is 85 octane. Will this be a problem? Should I go with the 87?

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At higher altitudes cars require a lower octane than at sea level. (Less air, lower air pressure, lower pressure in the cylinders) In the front range of Colorado all you see for regular is 85. Same in SLC. At your altitude it works like 87 at sea level.

aaf709 · 11-30-2005, 12:53 PM

Comsumer Reports once did an article about the wastefulness of using a higher octane than needed. They suggesting trying a lower octane than required. If there's no problem (knocking or pinging) then use the lower. For example if a car's manual says 94 try 90. If 90s too low try 92. In your case, you shouldn't have any problems, but if you do try 87.

MarkR · 12-03-2005, 04:22 AM

Tried this. Filled it up with Premium ULP and got better milage (.3l/100k) but it was still cheaper to run on STD ULP!

Jack 06 · 12-03-2005, 04:35 AM

narf is right.

hdrygas · 12-03-2005, 10:09 PM

Octane rating is not about energy/gallon it is about premature ignition with compression. Do a search and you will find multiple threads on this subject. When all variables are eliminated high octane gas provides lower M.P.G. than the one appropriate for the car.

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11-30-2005, 12:40 PM	#1
cap_ut Join Date: Nov 2005 Posts: 25 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	In the manual it states that one should use regular 87 octance gasoline. Where I live, Salt Lake City, UT, regular gasoline is 85 octane. Will this be a problem? Should I go with the 87?

11-30-2005, 12:53 PM	#3
aaf709 Ravenpaw of ThunderClan Join Date: Apr 2005 Location: San Diego, CA Posts: 3,839 My Car: 2005 Prius Model: Package: #6 Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	Comsumer Reports once did an article about the wastefulness of using a higher octane than needed. They suggesting trying a lower octane than required. If there's no problem (knocking or pinging) then use the lower. For example if a car's manual says 94 try 90. If 90s too low try 92. In your case, you shouldn't have any problems, but if you do try 87.

12-03-2005, 04:22 AM	#4
MarkR Join Date: Oct 2005 Posts: 19 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	Tried this. Filled it up with Premium ULP and got better milage (.3l/100k) but it was still cheaper to run on STD ULP!

12-03-2005, 04:35 AM	#5
Jack 06 Join Date: Oct 2005 Location: Winters, CA: Prius capital of US. 30 miles W of Sacramento Posts: 2,567 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	narf is right.

12-03-2005, 10:09 PM	#6
hdrygas Senior Member Join Date: May 2004 Location: Olympia Wa Posts: 3,650 My Car: 2004 Prius Model: Package: #9 Thanks: 0 Thanked 2 Times in 2 Posts Friends: 0	Octane rating is not about energy/gallon it is about premature ignition with compression. Do a search and you will find multiple threads on this subject. When all variables are eliminated high octane gas provides lower M.P.G. than the one appropriate for the car.