| Author |
Message |
    
JEFF EIERMANN
| | Posted on Wednesday, June 19, 2002 - 05:04 pm: | 
|
WHAT IS THE CONSENSUS ON USING "PREMIUM" 92-94 OCTANE GAS IN THE SERIES II? OUTSIDE OF ACTUAL DETONATION PROBLEMS, I HEAR THAT 89 OCTANE WILL SUFFICE. ANY THOUGHTS, EXPERIENCES? |
Paul L Schexnayder (Pablo83)
| | Posted on Wednesday, June 19, 2002 - 05:29 pm: |
|
Give the 89 a try. If your engine doesn't ping then you aren't damaging it. If it does start pinging add octane booster to the tank ASAP to avoid any damage. When the engine gets lots of miles on it the carbon buildup will cause detonation problems and you will need to switch back to premium. |
CarlT
| | Posted on Wednesday, June 19, 2002 - 06:04 pm: |
|
My truck seems to like the low octane stuff better... But I switch back and forth ever other tank, as I don't like the usually higher sulfur levels in the low octane US gas. Can't be good for the systems...
Carl |
Anonymous
| | Posted on Wednesday, June 19, 2002 - 06:59 pm: |
|
I have a 99 DII and have been using Super Unleaded everytime. About 32,000 miles and the engine pings uphill. Should I be concerned ? |
Paul D. Morgan (V22guy)
| | Posted on Wednesday, June 19, 2002 - 07:29 pm: |
|
93 while in NC. But while I am in Philly, I can get 94. Runs great on the 94! |
Kennith P. Whichard III (Kennith)
| | Posted on Wednesday, June 19, 2002 - 11:55 pm: |
|
The LR Genuine workshop manual I have on CD says that the NAS Discovery IIs use the higher compression ratio version of the 4.0 V8. We actually do get more HP than those guys in the UK. It also says that this engine should be run with 95 octane fuel minimum, which you can't really get everywhere. I use Sunoco 94, and it runs quite better than on 93, with noticibly better gas milage, power, and smoothness.
The manual they give you when you buy it says 91, which I think is silly, since it has been my observation that the more octane I can get into her the better she runs. They just write that in there to preclude images of gas guzzeling and high running costs. Think about the 1965 Buick pushrod V8 that was the predeccessor of this engine. This must be why I can drive from PA to the outer banks on 1 tank of gas, and the EPA says it only gets 17 Mpg.
Cheers,
Kennith |
Erik G. Burrows (Erik)
| | Posted on Thursday, June 20, 2002 - 12:14 pm: |
|
Here in southern california, the highest octane fuel I can find, without going to 100 octane at $4/gallon, is 91.
Would it be worth it to try an octane bosting additive to my Chevron 91? |
Kennith P. Whichard III (Kennith)
| | Posted on Thursday, June 20, 2002 - 12:25 pm: |
|
Hmm...I've heard bad things about that, perhaps one of the more knowladgable people on this site would like to comment.
Cheers,
Kennith |
Craig Oakes
| | Posted on Tuesday, July 16, 2002 - 10:56 am: |
|
Not a good idea. The disco II has a "learning brain", if you you use a lower octane fuel, the brain senses this and retards the timing to compensate for the lower octane. Any savings you realize will be eaten up in poorer gas mileage and a slow running , poor performing engine. There is also talk that when you switch back it takes quite some time for the "drivability" to return . Personally ,I feel I have spent top dollar on a top performance vehicle, and to shave off a few pennies at engine expense is a bad idea. Hope this helps.
c.w. |
rans
| | Posted on Tuesday, July 16, 2002 - 11:35 am: |
|
17mpg? How the hell are you accomplishing that? I get 14+ on average, and I've tracked every ounce of fuel into this baby (99 DII). I've used midgrade on a few occasions which I think is 91, but mostly use premium with 93 octane. No knocks and about as much power as this dog of an engine can muster. It just amazes me that in a vehicle this refined that they would have a v8 that can only muster 176 HP and only on premium. My 6cyl 1.5 liter honda engine in my valkyrie has 100hp! |
Erik G. Burrows (Erik)
| | Posted on Tuesday, July 16, 2002 - 11:49 am: |
|
What about the 100 octane 'racing fuel' that some stations carry? Would the engine like this? Would it be a good idea to run a couple of tankfulls of the stuff every once in a while? |
Al Oliveira (Offroaddisco)
| | Posted on Tuesday, July 16, 2002 - 01:18 pm: |
|
Correct me if I'm wrong. You can use anything over 87 in the D2 but 91 or higher is needed to realize the engines potential (and a good tail wind). The learning aspect of it doesn't apply to the fuel used but the engines ECU will adjust for lower octane fuels. The engine is a high output engine but the ECU will compensate for lower octane. This was taken from the service manual...
"The ignition is calibrated to run on 95 RON premium fuel, but the system will run satisfactorily on 91 RON regular fuel. If the vehicle is refuelled with a lower grade fuel, some audible detonation will initially be heard. This is non-damaging and ceases when the system adaption is completed." |
Closed: New threads not accepted on this page