Use of premium petrol.

[FROSTYBALLS]

Interesting question and response on Honest John this week:

"I own a Toyota Yaris hybrid. What improvement can I expect if I change from regular unleaded  to BP Ultimate? KM

You’ll get more torque at low revs, allowing the epicyclic gears to go to a higher ratio earlier and save a little fuel, but the main thing is that you’ll be spared fuel-system problems: no gunge to gum up valves or injectors."

[mrpj]

Who answered the question? The last bit about gunge etc. seems to be a very misleading statement. I'd love to see their proof on that.  No doubt a quote from one of the oil companies which sell the stuff.

Typical oil company spin and marketing bs. 

[Mick F]

I tried the higher grade stuff in our Fiat500 Twinair some few years ago.  I had the sort of idea that the car ran better, but I wasn't really sure.  No proof either way, and perhaps I had some wishful thinking.  It made no difference to the fuel consumption at all, but it cost more!  How much of an increase in distance per tankful would be absorbed by the extra cost?

As I said, I couldn't honestly say if it made any difference to anything.  I've never even considered it sine then, and never even considered it for our Yaris Hybrid either.

Mick.

[Jonmartin]

I’ve tried it, but can’t say I was noticing much difference. Except in the cost, at least 10/15p a litre more. I can’t really afford that.

[martswain]

I have tried it in 2 x Prius, a Lexus CT200H and my current 2014 Yaris, both BP Ultimate and Tesco Momentum.

I noticed ZERO difference from my usual Tesco Unleaded, the only thing, as mentioned above, is a deeper hole in your pocket.

All cars main dealer serviced, never had fuel cleaner, no starting or running issues.

Going to have to use "Super" in my next Yaris, the GRMN likes to drink 97 RON or better !

[Mike J.]

As our hybrid cars have Atkinson cycle engines, the compression ratio is low so little chance of 'pinking', thus 95 octane is fine.

[Heidfirst]

3 hours ago, mrpj said:

The last bit about gunge etc. seems to be a very misleading statement. I'd love to see their proof on that.  No doubt a quote from one of the oil companies which sell the stuff.

Typical oil company spin and marketing bs. 

If they advertise it they have to be able to substantiate it or the ASA could get involved. When running my diesels I often used premium diesel (usually Shell) - not for any notion of improved performance or consumption but for the long term benefits of a cleaner engine.

[FROSTYBALLS]

1 hour ago, Mike J. said:

As our hybrid cars have Atkinson cycle engines, the compression ratio is low so little chance of 'pinking', thus 95 octane is fine.

The compression ratio of the current Yaris hybrid isn't particularly low at 13.4:1 - compared to the 1.0 litre at 11.5:1 and the 1.5 petrol at 13.5:1.

[Mick F]

Actually, if my facts are correct, they don't have Atkinson cycle engines, but simulated Atkinson.

Atkinson cycle uses different length strokes for inlet and exhaust etc, but ours have a standard normal crankshaft, so all cycles are equal.  I think it's the valve cycles that simulate the Atkinson, not the crankshaft.

https://en.wikipedia.org/wiki/Atkinson_cycle#/media/File:Atkinson_Engine_with_Intake.gif

Mick.

[Mike J.]

38 minutes ago, FROSTYBALLS said:

The compression ratio of the current Yaris hybrid isn't particularly low at 13.4:1 - compared to the 1.0 litre at 11.5:1 and the 1.5 petrol at 13.5:1.

But that is on the exhaust (expansion) stroke. On the inlet (compression) stroke, the inlet valves stay open longer than normal, reducing the real compression.

[Mike J.]

10 minutes ago, Mick F said:

Actually, if my facts are correct, they don't have Atkinson cycle engines, but simulated Atkinson.

True, a low compression engine on compression stroke and high on the expansion  - like a short stroke on compression and long stroke on expansion - like an Atkinson engine.

[YarisHybrid2016]

The Hybrid just keeps the inlet open after BDC, and pushes some of the fuel out again while the valve closes, then you get the compression. Less fuel, less compression, but I wouldn't want to say how much less. Apparently not much if the spec is for the actual compression, not the theoretical.

I tried the premium fuel, and didn't see any difference. It costs a lot more than any savings would yield, so on basic economics alone it is not worth it.

Honest John post is being anything but.

Quote

You’ll get more torque at low revs, allowing the epicyclic gears to go to a higher ratio earlier

  Do any of these people research anything?

Edited March 1, 2018 by YarisHybrid2016

[bathtub tom]

Just had my MOT done at 30K miles. The HC are up from 4 to 16 PPM (limit 200) and the CO from nought to 0.01% (limit 0.2). Maybe due to the cold weather and a richer mixture, but I think I'll try the odd tankful of premium over the next year.

[Cyker]

I used to use V-Power diesel in Old Yaris every 3rd or 4th tankful just to try and stave off the performance loss I used to get from doing mostly urban driving; It seemed to do the trick as I never really experienced the drop off in performance I did when I was just running it on Sainsburys finest alone. (And me taking it on weekend hoons probably helped too ).

It also had a noticeable effect on performance; The most obvious one was the engine ran a lot smoother and less clattery - You could feel and hear the change immediately after firing up the engine after filling a near-empty tank. The other effect was weirder - There was a noticeable loss in torque and I'd find myself shifting maybe 500-700rpm later than normal because the car felt like it was struggling more at lower RPM. However I found I could run the car to higher RPMs - With Sainsburys I'd normally avoid going past 3000rpm because the engine would vibrate quite alarmingly and didn't really provide any extra pull, but with the V-Power I could take it to 4000 and it'd still pull.

So I mostly saved the V-Power for when I'd knew I'd be hitting a motorway!

 

I haven't tried it in New Yaris yet - I'm trying to get a feel for what it will do with normal Sainsburys petrol as a base-line for comparison, but with mpgs in the low-mid 40's it's frankly pretty **** compared to the 65+ I was getting in Old Yaris. It's actually getting worse as I'm losing patience with the lack of torque and have been resorting to just dropping gears and revving the nuts off it when trying to overtake things on the motorway!

I find I'm getting through twice as much fuel as I did in Old Yaris so I may try some V-Power in it in the hope that all the VVTi and electronic ignition magic will be able to take advantage of it and give me some much desired torque back!! Or if nothing else, to give the valves and fuel system a bit of a clean!

 

[Mick F]

I spent many years in the Royal Navy, and at one point as I remember,  was away on the ship for a few months whilst Mrs Mick F used the car locally just running to the shops once a week or so.  The car was a Talbot Horizon and was fairly new.

After getting back from sea, I had a drive and the car felt very sluggish indeed (even for a Talbot Horizon!).  Within a week or so, we took a drive up the A38 dual carriageway to Newton Abbot, and I floored it.  80mph for the run from Plymouth to the Newton Abbot turn-off and back again later. From that day on, the car worked and ran so much better because I made sure that the car always had a good run once a month or so ................. and I think that did the trick.

Car engines like to be used.  They like a good blast from time to time, and enjoy a good long run.

Mick.

[YarisHybrid2016]

I've heard it said "a car driven slowly, will drive slowly".

By driving them hard occassionally and giving them a good run gets heat into everything and burns off the rubbish that can accumulate. This likely explains the quote.

https://www.ngkntk.co.uk/index.php/technical-centre/spark-plugs/fouling-range/

[fordulike]

2 hours ago, YarisHybrid2016 said:

I've heard it said "a car driven slowly, will drive slowly".

By driving them hard occassionally and giving them a good run gets heat into everything and burns off the rubbish that can accumulate. This likely explains the quote.

https://www.ngkntk.co.uk/index.php/technical-centre/spark-plugs/fouling-range/

Great info @YarisHybrid2016

I regularly rev the Aygo to 6k rpm, not by choice, but needed to join a dual carriageway safely. It's uphill, so 2nd gear floored is the only way to reach speed. My spark plugs at 30k were looking in rude health. I'm a firm believer in the Italian tune-up concept.

[Mick F]

14 minutes ago, fordulike said:

 I'm a firm believer in the Italian tune-up concept.

Love it!  

[Justhandguns]

On 10/03/2018 at 8:13 AM, YarisHybrid2016 said:

I've heard it said "a car driven slowly, will drive slowly".

By driving them hard occassionally and giving them a good run gets heat into everything and burns off the rubbish that can accumulate. This likely explains the quote.

https://www.ngkntk.co.uk/index.php/technical-centre/spark-plugs/fouling-range/

I am not sure if it helps with the spark plugs, but it does help for some parts like the gearbox and certain valves in the car. Imagine how many times you use the 5th (or even 6th) gear while you drive in town.