Which Gas To Choose?

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Apr 22, 2012 | 07:48 PM

#21

oilspotLR

Winching

Joined: Feb 2012

Posts: 610

Likes: 1

Quote:

Originally Posted by Savannah Buzz

I found this page in the LR3 "rave" I downloaded, it does say premium (91) for NAS, ROW says 98 (using a different measure). This is for the V6.

I wonder why though, especially if the ford v6 in the f150/explorer doesn't need premium....

Apr 22, 2012 | 09:49 PM

#22

Banzai Jimmy

Rock Crawling

Joined: Jan 2011

Posts: 467

Likes: 36

From: Aurora, CO

Quote:

Originally Posted by oilspotLR

I wonder why though, especially if the ford v6 in the f150/explorer doesn't need premium....

Different timing curve would do it. If LR put a more aggressive timing curve into the computer, then you'd need the higher octane to prevent pre-ignition/detonation.

Don't know if that's it (assuming the internals of the engines are the same) - just an idea off the top of my head.

Apr 23, 2012 | 07:03 AM

#23

roverguy67

Three Wheeling

Joined: Mar 2011

Posts: 82

Likes: 1

From: Holyoke MA

I have had my 2000 DII since 1999 and have only run 92 octane or higher..... It runs BAD on regular( I can ALWAYS tell when my step son has put bad fuel in my truck!!). I would suggest only premium fuel......just sayin...

May 14, 2012 | 08:42 AM

#24

jbunner

Three Wheeling

Joined: Aug 2011

Posts: 66

Likes: 0

From: wv

My '95 takes premium. I have tried the lower octane, won't go up the hills in WV. Knocks, etc. The manual say 95 octane which I can't even find. The premium here is 93 octane. I even tried putting octane booster in to no avail. Just have to bite the bullet and pay for premium if I want to drive the thing.

May 14, 2012 | 07:56 PM

#25

Spike555

Team Owner

Joined: Jun 2007

Posts: 26,212

Likes: 98

From: Grand Rapids MI

Quote:

Originally Posted by jbunner

95 octane is in Europe, not the US.
Octane booster actually lowers your octane rating and even if it did work think about it.
$5 for a bottle of octane booster for every tank of gas, or just pay the extra $5 to fill up with premium.

Oct 9, 2012 | 11:20 PM

#26

rallyemax

3rd Gear

Joined: Oct 2012

Posts: 3

Likes: 0

Quote:

Originally Posted by Spike555

Well on a non dizzy engine the knock sensors retard the ignition timing to adjust for the lower octane fuel.
On a dizzy engine YOU have to retard the ignition timing to adjust for the lower octane fuel, if you dont you will get spark knock (you may not hear it) and as we all know from high school auto shop spark knock over extended time will destroy a engine.
How much you need to retard the ignition timing I have no idea.
Now I will confuse you even more, there were a small number of low compression 3.9's imported to the US, those only require 87 octane, the compression ratio on those engines is 8.35:1 compared to the 9.35:1 on the "high" compression engines.
I do not know how to tell which engine you have.

On a D1, the compression ratio should be stamped immediately above the engine serial number.

If the ratio is 8.13, the manual states to use 91 RON, which equates to 86-87 "American" octane (AKI).

If the ratio is 9.35, the manual states to use 95 RON, which comes out to 90-91 "American" octane (AKI).

Remember those figures are for sea level. Lower octane fuel may be used at altitude (this is why in the Rocky Mountain states, fuel is sold at 85, 87, and 91 octane...in lower-lying regions, it's sold at 87, 89, and 93, respectively).