Good evening all! I've always used vpower 91 octane in this mint baby for the past 8 years. Now Shelll has upgraded their vpower fuel to the best yet. Anyone use this?
Nothin beats a Jag.

 

I use Shell all the time in my V8, but I use 93.

 

If it avoids ethanol then it'll run a bit better but cost quite a bit more I suspect. Personal choice.

 

When I bought my Jag it had an intermittent skip at idle I could feel in the seat of my pants..Shell 93 and a shot of Lucas makes my S-Type 3.0 happy..

 

While we're talking about gas I live near marinas and several gas stations have no ethanol gas 90 octane.. Any thoughts and suggestions ?

 

What Octane does your car require?
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Octane, ethanol, additives and brand names all in one post. Be still my bleating heart, it must be Christmas in July.

- All gasoline comes from one, maybe two regional, refineries irrespective of which brand name it carries.

- The only difference from one brand to the next is the additive package. There is not enough difference between one brand and another to declare one a clear 'winner'. Our Jags by all accounts appear to have low sensitivity to additives in general as compared to some cars which must use 'Top Tier' fuels to avoid deposits.

- S-types achieve full rated performance on 91 AKI (95 RON) octane fuel. Anything higher than that is pure waste. Anything lower gets into the realm of potential reduced performance or increased consumption due to the knock sensors cutting back on ignition advance to fend off detonation. On the other hand, those that have run the cars on low octane fuel (87 AKI, 91 RON) appear to notice little or no effect.

- E10 (10% ethanol) fuels reduce fuel mileage by 3% or maybe 1 MPG on an S-type. Most drivers see a larger variation from tank to tank than that without changing fuel so pinning down the effect of ethanol in low concentrations is difficult. It is sheer folly to pay much extra for non-ethanol fuel or to drive any distance to obtain it.

 

My manual says premium fuel. Here, that is 93. Regarding ethanol, I find your information about S-types good news. Our Chevrolet models vary so much, it really bothers us. 30% in the Impala and 18% in the HHR. I have only used 93 in this car and I only use Shell, BP, and Chevron. My mileage is 23.4-24.3 hwy and about 18.4 for in town and highway combo. It seems good for a 2 ton V8 vehicle.


Thanks for the info.

 

Have to disagree...

My S-type manual says "The preferred fuel should have an octane rating OF AT LEAST 95 RON... Using fuel with a lower rating can lead to engine damage".

Nowhere does it say that full-rated performance is achieved with 91 AKI. Rather, it suggests that 91 AKI is the MINIMUM TO AVOID ENGINE DAMAGE.

As for ethanol, just ask Brutal what he thinks...

 

No kidding...........

Here's what the manual actually says:

" Using unleaded fuel with an octane rating
lower than recommended can cause
persistent, heavy ‘spark knock’ (a metallic
rapping noise). If severe, this can lead to
engine damage.
If a heavy ‘spark knock’ is detected even
when using fuel of the recommended
octane rating, or if you hear steady ‘spark
knock’ while holding a steady speed on
level roads consult a Jaguar Dealer to
have the problem corrected.
Failure to do so is misuse of the vehicle,
for which Jaguar Cars Limited, is not
responsible. However, occasional light
‘spark knock’ for a short time while
accelerating or driving up hill, may occur."

A little different and certainly more liberal and informative than your dire interpretation.

 

OK, I'll reword my original liberal statement. Your comment:

Is, in my opinion, hogwash. We already have your opinion, so why not it rest.

 

It's more than 'opinion', it's fact whether you wish to continue denying it or not

SAE testing procedures for Net HP require that the car be in stock, standard configuration as would be delivered to a retail customer. This includes the octane rating of the fuel being used. If Jaguar says that the car makes X horsepower and recommends Y octane rating, it must deliver that power rating on that fuel. Hence, the engine delivers full rated performance on the stated fuel.

As to whether the engine would deliver additional power with even higher octane levels, this can only happen IF the engine power is being suppressed while on a lower rated fuel. In other words, the engine would need to experience sufficient detonation on 91 AKI that the knock sensor would command a reduction in ignition advance and modifications to the fuel delivery curve. Putting aside your endless assertions that any detonation=engine destruction, I'd don't know of any OEM that would send a car to market knowing full well that the recommended fuel would send the engine into a constant state of detonation and resultant ignition clawback.

Despite these cars being in the field since 1999, there's no credible evidence from any owner that using fuel higher than 91 AKI has any affect at all, other than draining the wallet.

In the same vein, there's no evidence of any S-type being damaged by use of fuel less than 91 AKI. I would think that in 16 years, such proof would have surfaced.

It's interesting to note that the wording in present day owner's manuals for JLR cars using essentially the same engine states:

V6 and V8 engines: Jaguar Land Rover Limited
recommends the use of premium unleaded
gasoline with a minimum octane rating of 91
AKI (Anti-Knock Index) to contribute to peak
performance, fuel economy and driveability.

If premium unleaded fuel is not available, you
may use unleaded fuel with a lower octane
rating, down to a minimum of 87 AKI, but this
may reduce engine performance, increase fuel
consumption, cause audible engine 'knock', and
other driveability problems.

No mention of zombie apocalypse engine destruction. Perhaps JLR has a market research group that reads this forum and recommends clarifications to the wordings of owner's manuals?

If we're going to suggest that things be given a rest, how about it?

 

Yawwwnnn... Whatever, Mikey.