Thread: What Octane Petrol for 4L V8

Originally Posted by garrycol

There is no low comp model - in Aust the engines in all models were low comp except for the last of the D2s which when to higher compression.

Garry

yes, mine is the high comp one

Originally Posted by garrycol

There is no low comp model - in Aust the engines in all models were low comp except for the last of the D2s which when to higher compression.

Garry

Not so sure about that Garry. My 98 D1 is a HC 9.35:1, and my understanding was that it was the last of the D1s that went HC, and not the last of the D2s.

I have also high compression 4L V8. Running mostly 98, sometime 95. When using 91 (only in emergency situations) there is pinging. Using 95/98 the consumption is 15.5L/100km on highway 110km/hr. Around the town it is mostly 20L/100km... J

I'm led to believe that LR specify "unleaded" as the fuel to use in the 4L but did some digging & it seems that the minimum octane rating available in the UK is 95 & their premium is 98 therefore suggesting that regardless of the differences between labels on fuel, 95 as a minimum should be used. I used to get major pinging running 91 so changed to 95 or 98 if I feel she's running & little rough at idle & 2 tanks of 98 seems to clear up that issue. I also seek out BP servo's. Have never tried E10 fuel thus far.
Cheers
Mat


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Originally Posted by Discobaker

I also seek out BP servo's. Have never tried E10 fuel thus far.
Cheers
Mat

"Unleaded" ie 91/92 octane has been E10 at BP for some time - that is why I do not get unleaded for my 101 from them.

Garry

I have a 2003 V8 (D2a) and use E10 (91) all the time.

No problems at all.

Regards
Andrew

Originally Posted by garrycol

"Unleaded" ie 91/92 octane has been E10 at BP for some time - that is why I do not get unleaded for my 101 from them.

Garry

Probably should've been a bit more clear, I only use 95/98 juice, never base unleaded (91/92) & therefore have not used E10 in my Disco.

Originally Posted by PhilipA

Check the compression ratio stamped between 2 and 3 next to the engine number.
If it is 8.13:1 ( or near that,I think they changed slightly in the 4.0) then use normal 91 octane unleaded.
If it is 9.35 use 98 octane.
D2As changed at some point from 8.13 to 9.35.
Regards Philip A

ok, just checked and on mine it says CR9.38:1.

I reckon the CR is compression ratio, but not sure about the 9.38:1 (any idea?)

cheers
Mark