Petrol grade...

[TomcatUK]

Recently purchased a Lexus IS 300h..... great car.

I regularly put BP Ultra (97 Ron) in my previous car (VW Eos 1.4 Sport), and felt that it benefitted from this grade of petrol.

I am quite happy to use this grade in my Lexus but was advised against this by the salesman, on the basis that “it will burn out the valves”

Any comments / advice would be appreciated......

[wharfhouse]

5 minutes ago, TomcatUK said:

Recently purchased a Lexus IS 300h..... great car.

I regularly put BP Ultra (97 Ron) in my previous car (VW Eos 1.4 Sport), and felt that it benefitted from this grade of petrol.

I am quite happy to use this grade in my Lexus but was advised against this by the salesman, on the basis that “it will burn out the valves”

Any comments / advice would be appreciated......

Some so-called sales people do make you wonder... 

[65mike]

Hi all.

John i think the sales man is incorrect here it may not improve your mpg by much or at all but i very much dought it will do any harm otherwise it would not be sold.😐

I have used BP ultima fuels and Shell equivalent before on a previous car but gave up due to price.😐

65mike

[Thackeray]

The car manual says the fuel should be "Research Octane Number 95 or higher". 

[NemesisUK]

I have only ever used V-Power in my RC300h

As posted above the handbook states the minimum octane, no maximum.

[Pink]

The Atkinson cycle ICE is optimised for economy rather than power, so I don’t imagine there’s much BHP advantage with the higher octane. I just run regular Shell but put in V-Power around every 5th fill for the cleaning additives. 

[Ziggy1024]

8 hours ago, TomcatUK said:

Recently purchased a Lexus IS 300h..... great car.

I regularly put BP Ultra (97 Ron) in my previous car (VW Eos 1.4 Sport), and felt that it benefitted from this grade of petrol.

I am quite happy to use this grade in my Lexus but was advised against this by the salesman, on the basis that “it will burn out the valves”

Any comments / advice would be appreciated......

The short version: the salesman is talking nonsense.

Slightly longer: higher octane fuel will provide a performance benefit (beyond any claims WRT 'cleaning' etc.) only if the engine is mapped to take advantage of the increased resistance to knock that such fuel offers. This could be through more aggresive ignition timing (which would be retarded if knock was detected e.g. through the use of lower octane fuel), or (in a forced-induction engine) through boost levels. Without any details on how the engine management system on your car works I can't comment on whether it has any capacity to take advantage of higher octance fuel. The concept of it having a negative effect and 'burning out the valves' is nonsense, though.

[olliesgrandad]

I now use the cheapest fuel as the performance advantage would be negligible with all the power in my car. I occasionally put redex in the tank, but my car is always running hot. Last week I did 1000 miles in a loan IS300h using standard fuel and the performance was extremely good with mpg in excess of 50mpg.

I remember when I had an Audi Quattro there was a plug type switch mechanism to alter between normal and super fuel. Seem to remember my 2.8 Z3 also was adjustable. 

[DJ Les]

A few years ago I had a Toyota Celica GT4 Turbo which was newly imported from Japan with 100k (60,000 miles) on the clock. I filled my first tank with standard 'supermarket petrol' 95RON. It ran like crap, poor acceleration and misfiring. I joined the GT4 Owners Club on the internet and found that, the British version of the GT4 ran quite happily on 'supermarket petrol', but, the import version required 97/99RON petrol. I found a Shell garage 8 miles from home that had VPower (or was it Powermax back then?). After filling up with that there was a major difference in performance and no more misfiring. I had the car for 3 years and always had to watch the fuel gauge til quarter full then head off to the garage.

When I got the Lexus 3 weeks ago the first thing I checked for in the manual was what octane fuel it required. Was very pleased to see 95RON sold at my local Esso garage 1 mile from home, phew! 

 

[PaulWhitt20]

The only reason to use super unleaded in the IS300h is to boost the profits of the petrol companies.

[Hadrian]

20 minutes ago, PaulWhitt20 said:

The only reason to use super unleaded in the IS300h is to boost the profits of the petrol companies.

Quite right.

Always use the recommended fuel.

[rich1068]

My '05 Saab 9-5 Aero is the first car I've ever owned that specifies the use of 98RON in the handbook. It even warns against the use of anything else. 

I can continue my V-Power affectation with a clear conscience.

Goes like the clappers too.

[Ziggy1024]

10 hours ago, rich1068 said:

My '05 Saab 9-5 Aero is the first car I've ever owned that specifies the use of 98RON in the handbook. It even warns against the use of anything else. 

I can continue my V-Power affectation with a clear conscience.

Goes like the clappers too.

In this case, Trionic 7 effectively reduces the torque request when it senses knock. It'll run fine on normal fuel if you need to though - no need to panic if you get caught short!

[m4rkw]

Unless the car requires it you will see no benefit from using higher octane fuel. It certainly won't damage anything though. The octane rating is just how much compression the fuel can take before it spontaneously combusts.