Reg or Hi test

Reply Subscribe

Thread Tools

Search this Thread

May 27, 2007 | 09:43 AM

fb4u2nv

Thread Starter

Novice

Joined: May 2007

Posts: 18

Likes: 0

From:

Reg or Hi test

Is there any significant advantage to running Hitest gas in an EVO engine? Isn't the compression ratio fairly low compared to the new engines?

Thanks

May 27, 2007 | 09:57 AM

HD7585

Outstanding HDF Member

Joined: Nov 2006

Posts: 3,269

Likes: 12

From: NJ

RE: Reg or Hi test

My EVO pings on anything less than hi test

May 27, 2007 | 11:02 AM

ssls6

Road Captain

Joined: May 2006

Posts: 582

Likes: 50

From: South Park, CO

RE: Reg or Hi test

The lowest octane that doesn't cause pinging is your best choice (and probably has the least ethonol in it). My EVO is fine with 87.

May 27, 2007 | 11:16 AM

dert

Road Master

Joined: Jun 2005

Posts: 916

Likes: 1

From:

RE: Reg or Hi test

87....Shell only unless Im somewhere thats its not available

May 27, 2007 | 11:22 AM

randy78045

Big Kahuna HDF Member

Joined: Oct 2006

Posts: 30,634

Likes: 0

From: Laredo, TEXAS

RE: Reg or Hi test

Da book says to use premium, so that's what i use... practically nothing will destroy an engine faster that detonation...

May 27, 2007 | 11:44 AM

MikeyB

Tourer

Joined: Dec 2005

Posts: 279

Likes: 0

From:

RE: Reg or Hi test

A stock Evo with 8.5 compression should run just fine on regular unleaded. If it doesn't you might want to fatten up the mixture.
My Evo gets nothing but 87 including the EPA mandated 10% ethanol blend.

MikeyB

May 27, 2007 | 11:58 AM

HGM

Road Warrior

Joined: Apr 2007

Posts: 1,952

Likes: 15

From: Senoia, Ga., by way of Miami, Fl..

RE: Reg or Hi test

A freind told me he has been running 87 with an octane booster.. Seems like it might work well and you may even come out cheaper in the long run. The main thing that concerns me with 93 is that no one is using it these days (at least not many folks). This leads to the fuel sitting for longer periods and possible contamination... Just a thought.. I curently run 93, but will likely try the booster idea..

Trending Topics

1979 XLH 1000 - a good year?

111

2.6k
Oil pressure sensor 2002 Heritage Classic

23

471
What would cause this Front Tire failure?

22

939
FLT to FLHS

22

471
Top end rebuild Go Big or Stay Home?

97

3.6k

May 27, 2007 | 12:50 PM

pococj

Seasoned HDF Member

Joined: Dec 2004

Posts: 11,068

Likes: 1,473

From: Texas! Ya mean there's someplace else?

RE: Reg or Hi test

Dumping booster in there is gonna cost more than buying premium. As far as sitting in the tank - how long you reckon that gas sits in a ship while it making its way here from Saudi Arabia?

I sometimes run the premium, but usually run 89 octane. I can run 87 in cooler winter weather, but in Texas it might be a high of 30F today, and 85F tomorrow. Easy enough to try the different octanes, and then use the one that suits your bike and your riding style best.