will it do anything bad? - Page 2 - MustangForums.com

GT S197 General Discussion This section is for technical discussions pertaining specifically to the V8 variation of the 2005 and newer Ford Mustang.

will it do anything bad?

Old 06-13-2007, 04:04 PM
6th Gear Member
Join Date: Feb 2005
Location: AZ
Posts: 11,534
Default RE: will it do anything bad?

ORIGINAL: 22kart22

do you guys always use regular?

Well, there are higher octane fuels which have a higher flashpoint to retard the timing in high preformance engines. Thats why racecars use racing gas. So I figured that putting premium may change the timing alitttle....
Computer controls timing, not the fuel. That's what a tuner is for. Altering the computer program that controls the timing to take advantage of the higher octane. What you're thinking of is an older engine with many miles on it and some mild pinging/knocking. Higher octane may help there. Again, on your engine, higher octane without a tune is a waste of $$$ period. Go take it to a dyno and see for yourself.

As for racing gas...that's because racing engines have the timing cranked way up and run much hotter spark and engine temps so they need that higher octane to keep from detonating.
Derf00 is offline  
Old 06-13-2007, 04:08 PM
6th Gear Member
Join Date: Feb 2005
Location: AZ
Posts: 11,534
Default RE: will it do anything bad?

ORIGINAL: Drop Top 06

ORIGINAL: owero01

If you don't have a tune for premium, its ok to use it ocassionally. It helps to keep the engine clean.
How exactly does it help to keep the engine clean? The octane rating detemines at what point combustion occurs. Say we have a car that's tuned for 87 octane. Its my understanding that 93 fully combusts at a higher point than 87 does, thus leaving miniscule particles behind. Those particles don't really have a noticeable affect on performance, but I would imagine after 100,000 miles or so, there might be some buildup... I could be wrong though..
All fuels have certain detergents that are present regardless of brand. Otherwise they would not have EPA or government approval. All octanes of a brand of gas have the same additives regardless of what their commercials say (premium has XYZ additive)...

i.e. Chevron Techron is their 'special' brand name additive. It's present in their 87, 89, and 91/93 octane.

Rather than blow the money on the higher octane fuel for percieved cleaning abilities, just buy the cleaner concentrate at the auto parts store and addit next time you fill up.

So to sum it up, higher octane fuel does not have better cleaning ability than lower octane.
Derf00 is offline  
Old 06-13-2007, 04:11 PM
2nd Gear Member
Join Date: May 2005
Location: Groesbeck, TX
Posts: 361
Default RE: will it do anything bad?

OK, i got better mileage before a tune and using 93 octane but it was still only 1 almost 2 MPG so it wasn't worth it. Went to 93 octane tune and get much better mileage and more power.

In conclusion, putting higher octane w/o a tune won't hurt, but it won't help much either.
dirtydeedsinc is offline  
Old 06-13-2007, 04:25 PM
3rd Gear Member
Join Date: Mar 2007
Posts: 753
Default RE: will it do anything bad?

Just to put it out here. Octane rating is the ability to resist detonation. A higher rating the more the resistants to detonation.Not to be confused with pre-ignition.Which would be a hot spot igniting the mixture before the plug does(Too hot of a plug/carbon build up on the piston..etc.)So the extra power from higher octane comes from the ability to advance timing without getting into detonation(Too the limit of the octane)But from what I understand all pump gas (87-9...) has the same BTU, which is what puts off the heat.But racing fuel has a higher octane +more BTU's.
Eleanor06 is offline  
Related Topics
Thread Starter
Last Post
V6 (1994-2004) Mustangs
10-05-2015 06:52 AM
2005-2014 Mustangs
10-02-2015 09:06 AM
5.0L GT S550 Tech
10-02-2015 05:55 AM
S197 Handling Section
09-30-2015 11:13 AM
General Tech
09-28-2015 08:36 AM

Thread Tools
Search this Thread
Quick Reply: will it do anything bad?

Featured Sponsors
Vendor Directory

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.