Petrol - Regular or Premium?

[JeffL]

Got to raise this old chestnut again (got an itch about it!). It's been discussed on the IS forum and maybe others but I'm specifically interested in responses from owners of Lexus vehicles with 3.0Litre Petrol Engines as I have the GS300 3.0L Petrol. I've owned my 11 year old (2007) GS300 for the last 9 years and always used Tesco Regular Unleaded with no apparent problems. However, Honest John (honestjohn.co.uk) always, very strongly, recommends Shell V Power as he says it keeps the engine components cleaned/lubricated which gives better performance and improved MPG. What's prompted me to start a discussion on here is that I've noticed a slight hesitation when accelerating and I'm not sure if it is engine or gearbox related. I sometimes happens when pulling away from standstill but can happen when taking foot off accelerator pedal to brake a little and then accelerating again as you do at a roundabout for example when you don't actually have to stop. I'm not a boy racer when driving locally (a young 70 year old), I just drive normally enjoying the luxury of the car, although I do like to get where I'm going when on a long motorway journey. On these long journeys the car performs wonderfully! The car has been serviced every 12 months by my indie for the last 9 years and is due again in November. I noticed on last year's bill that 'fuel treatment' at £12.20 had been added for the first time in 9 years. I THINK they said it was to get the emissions to the right level for the M.O.T. (I'm not mechanically minded so just let them get on with it.) I'm now wondering if that meant the engine wasn't as clean as it could have been if I'd used a Premium petrol?

So do you use supermarket regular or premium or do you use a  branded fuel like Shell V Power and what have you experienced with your chose petrol?

Note: I will be having the transmission fluid changed at the next service (discussed on another thread) so if it is the gearbox causing the hesitation I'll then know that that angle has been covered.

Thanks in anticipation.

 

 

[AmbroseJohn]

Regular without doubt.

Using Premium in an engine that doesn't require it, is just a waste of money. You're just paying for higher octane required by the higher compression of performance engines, which is not required or recommended by Lexus. 

Fuel providers will tell you different but it's their job to separate you from your money, don't believe them. 

[Britprius]

As the above. A total waste of money buying premium in fact it can reduce your MPG.

John.

[scudney]

Everyone to their own,still works out cheaper than buying some of the fuel additives out there

[AmbroseJohn]

5 minutes ago, scudney said:

Everyone to their own,still works out cheaper than buying some of the fuel additives out there

Additives which are neither required or recommended by Lexus.

[Britprius]

The power of advertising never ceases to amaze me. 

John.

[NemesisUK]

Well premium certainly made a positive difference in my AMG and I'm continuing to use it in my RC. Have used nothing but V-Power since purchase. The extra £5 or £6 per tank is insignificant in the scheme of things..

[royoftherovers]

1 hour ago, Britprius said:

The power of advertising never ceases to amaze me. 

John.

Lord Leverhulme is quoted as having once said "50%of my advertising budget is wasted, but I do not know which 50"

[scudney]

advertising does nothing for me as most claims are over exaggerated and most don't even live up to the hype😊 

[C Mclean]

Just using the premium grade from COSTCO, cheaper than anyone else locally.

[Initial P]

Since buying my GS300 in Jan this year apart from one time when I used BP I've used Shell every other time & never used supermarket grade, I sometimes use V Power & get more MPG.

I have some family members who work in the fuel retail sector & there boss gets offered the supermarket fuel about 5-7K cheaper per tanker than the normal stuff which would allow them to make a bigger profit but they take the good stuff.

OT:

Still my car has been off the road since Friday with something completely different, I have to say I expected more from a Toyota sub brand @ 80k miles, luckily work leant me my work van 🙂

[Richiano]

51 minutes ago, Initial P said:

Since buying my GS300 in Jan this year apart from one time when I used BP I've used Shell every other time & never used supermarket grade, I sometimes use V Power & get more MPG.

I have some family members who work in the fuel retail sector & there boss gets offered the supermarket fuel about 5-7K cheaper per tanker than the normal stuff which would allow them to make a bigger profit but they take the good stuff.

OT:

Still my car has been off the road since Friday with something completely different, I have to say I expected more from a Toyota sub brand @ 80k miles, luckily work leant me my work van 🙂

Can i ask what is wrong with it as i also have a GS300?

[NemesisUK]

I'm sure there's nothing 'wrong' with it per se just that it will have fewer or cheaper additives?

[Initial P]

52 minutes ago, Richiano said:

Can i ask what is wrong with it as i also have a GS300?

Alternator died leaving me at the aid of the AA on Friday morning (St Albans A414) my indie said that he could get the after market part asap but would need a few days to get the proper Denso part which only cost £30 more so I waited.

[Initial P]

Does anyone remember that fuel crisis years ago where by Morrison's fuel damaged engines ?

[Britprius]

21 hours ago, NemesisUK said:

Well premium certainly made a positive difference in my AMG and I'm continuing to use it in my RC. Have used nothing but V-Power since purchase. The extra £5 or £6 per tank is insignificant in the scheme of things..

Forgive me for saying this, but that's like saying I put 2 stroke oil in my 2 stroke mower, and that runs perfectly on it. Because a given fuel runs in one manufacturers car does not translate into it will perform better in an other of a different make.
To me that £5 or £6 pounds saved is another gallon of fuel that will take me another 40 miles rather than loosing 1 or 2 MPG using a higher octane fuel that the engine was not designed for.
Yes cars with engines designed to run on high octane fuel will get better MPG from that fuel against a lower grade, but that does not translate into a higher grade will give more MPG in engines not designed for it in fact the reverse is the case. Check calorific values of petrol grades.

John.

[NemesisUK]

Agree totally

The point I was trying to make is in the AMG the engine produced more power and more smoothly. No interest in mpg.

In the RC again I've no interest in mpg and still believe the additional cleaning additives are beneficial, well certainly not detrimental but as I've never used anything but V-Power from mile 0 I cannot really compare performance. I believe the engine does adjust settings depending on fuel quality though.

[ColinBarber]

15 hours ago, NemesisUK said:

I'm sure there's nothing 'wrong' with it per se just that it will have fewer or cheaper additives?

Fewer isn't a bad thing, means you get more petrol per litre of fuel.

[NemesisUK]

9 minutes ago, ColinBarber said:

Fewer isn't a bad thing, means you get more petrol per litre of fuel.

Measurable in laboratory testing but is it really significant in everyday driving, with all the inherent uncontrollable variants that come with it? 

[Prince Bob]

When I had one I always used super unleaded as I thought direct injection petrol engines were prone to carbon build up. This may have been marketing hogwash to get me spend more money on fuel though

[ColinBarber]

14 hours ago, Prince Bob said:

When I had one I always used super unleaded as I thought direct injection petrol engines were prone to carbon build up. This may have been marketing hogwash to get me spend more money on fuel though

The direct injection engines with the older D-4 Toyota system (IS250 series II, GS300 series III for example) are prone to carbon build up because there is no fuel washing over the backs of the intake valves. It doesn't matter what grade of fuel you use because it doesn't touch the valves.

Newer models now use the D-4S system which combines port injectors, to keep the valves clean, and direct cylinder injectors.

[Dapprman]

Number of things to take in to account.  First on a world car the ECU will be set to test against knock and advance the timing over time until fueling is optimised.  This is because the cars have to work with all forms of fuel (her petrol) and in the US, a big market for Lexus, the unleaded fuel quality is quite poor.  We will actually get better performance over here on our 94 RON (regular unleaded fuel) as a result, however we will get a slight improvement driving the same way with higher octane fuel, such as Shell V-Max/Optimax/V-Power - which is 98 (and my preference from my days of highly tuned cars for track days).  The question is, does the improvement in fuel economy make up for the increase in cost.  V-Power is presently about £1.41 a litre in my area compared to £1.32 for regular unleaded.  On Regular I've been getting around the 34.5-35 mpg mark for my regular drive, where as with V-Power I was getting 37-37.5, so about a 2.5 mpg difference, or a 7% difference, but for ~7% increase in price.  As I don't drive the car in performance mode it makes little difference cost wise to me.

Second.  Detergents. It certainly is a case that the detergents in Optimax (V-Power's former name) did make a difference on cars that had not had a suitable flush (such as redex) put through them.  In theory, these days, there's a few more petrols containing detergents, but while I no longer track day I know the consensus is still to stick to Shell V-Power (even though BP Ultima is 99 RON and Tesco do, or at least used to do 100 RON).  My rule and advice was to use one tank of V-Power/Optimax every 3-4 fills, and if you did not, over time, you would find a small drop in economy and performance over time.  Normally not noticeable as it is gradual.  The big difference was always the first usage of Optimax on a car over 3-4 years of age.  Over 10 years old and it could make a great initial difference, but only very small after that (hence no point is using V-Power every tank).

[st4]

The direct injection engines with the older D-4 Toyota system (IS250 series II, GS300 series III for example) are prone to carbon build up because there is no fuel washing over the backs of the intake valves. It doesn't matter what grade of fuel you use because it doesn't touch the valves.
Newer models now use the D-4S system which combines port injectors, to keep the valves clean, and direct cylinder injectors.

And that’s nothing the odd meeting with the 6500rpm marker won’t fix either. Every now and then an engine should get a workout.

I use branded regular fuels or supermarket super


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