Fifth Gear Unleaded/Super Unleaded Experiment

[dinkus 10]

you whatjimmywhatsit? :?

 

They put all types of fuels in every car (( ie a 95/97/98 ron fuel )) and tested the BHP...testing every single fuel available would be a bit of a bugga...it was just showing whether higher octane fuel increases performance like it says it does on the tin.

 

I got the impression they tried normal unleaded (95 RON) from a supermarket, 99(ish) RON Ultimate and 99(ish) RON Optimax.

 

My question was, why didn't they compare the higher octane fuels with the equivolant stuff from a supermarket?

 

I get your point that they were trying to show that the higher octane stuff can produce more power, but comparing it with el-crappo supermarket fuel seemed a bit unfair.

 

wanted to eat my own face

 

you liked that then :D :D

 

Yeah, loads. Especially Butty-Henders wonderful presenting :roll:

 

But the actual content was pretty good, much more realistic and informative than Top Gear, but it was just a bit annoying to watch.

[Chris VR6nos 0]

The biggest difference was in the torque figures!

 

 

 

chris

[dr_mat 0]

I got the impression they tried normal unleaded (95 RON) from a supermarket, 99(ish) RON Ultimate and 99(ish) RON Optimax.

 

Ultimate is 97 RON. Optimax is "unstated", but ~98.

 

I think the reason they did it this way was because they were looking to find out if there WAS a difference, not setting out to find out HOW BIG the difference was. Testing the marketing hype from shell/bp, more than anything else.

 

And the result of the whole thing really just shows that a car that's tuned for 98 produces more power on 98 (um, yeah, obviously!). If they'd had the technology to retune the clio with a bit more ignition advance to take advantage of the 98 octane, it too would have produced a fraction more power. But it wasn't, it was factory tuned for 95 octane, so it got no benefit.

 

The scooby was obviously going to benefit.. let's face it in japan they run them on 101 octane fuel ...

 

Interesting (but unsurprising) comments on the new TT and the Astra VXR though .. (yawn)

[Yandards 0]

[The scooby was obviously going to benefit.. let's face it in japan they run them on 101 octane fuel ...

 

Mmmnn 5 star fuel - proper stuff

 

The early 16v's were set to run old 4 star - i.e. 98 octane so a 16v should run closer to factory using this. The G60 were set to run on 95 octane unleaded (hence the CAT) so will need a bit of a fiddle with the distributor to get the best out of 98 octance. All other rados would be set up for 95 octane.

 

Running the higher octane fuel should mean a cleaner and more consistant burn in the cyclinder it should also help to reduce pinking as it the higher the octane rating the more you can compress it before it detonates prematurely.

 

Nothing worse than premature detonation.. :wink:

[dr_mat 0]

The early 16v's were set to run old 4 star - i.e. 98 octane so a 16v should run closer to factory using this. The G60 were set to run on 95 octane unleaded (hence the CAT) so will need a bit of a fiddle with the distributor to get the best out of 98 octance. All other rados would be set up for 95 octane.

 

Errr.. the VR is also setup to run 98 octane by default, obviously.. ;)

It has knock sensors to protect itself from rubbish petrol..

[Yandards 0]

Errr.. the VR is also setup to run 98 octane by default, obviously.. ;)

It has knock sensors to protect itself from rubbish petrol..

 

I'll get my coat :oops:

[Tempest 0]

The G60 also uses fuel maps in the ECU rather than entirely relying on the dizzy setting. The igintion point is advanced and retarded by the ECU based on a base-setting of 6° BTDC and the knock-sensor signals.

 

The older 8V (DX, JH) without an ECU and knock sensors did, however, require resetting the dizzy.

 

Tempest

[dinkus 10]

Errr.. the VR is also setup to run 98 octane by default, obviously.. ;)

It has knock sensors to protect itself from rubbish petrol..

 

I'll get my coat :oops:

 

It says so on the inside of the petrol flap :lol:

 

I have to say that I didn't seem to notice any difference at all running my VR on super-unleaded rather than Shell/BP normal unleaded. It certainly wasn't 4p a litre better, that's for sure.

[craigowl 0]

I have to say that I didn't seem to notice any difference at all running my VR on super-unleaded rather than Shell/BP normal unleaded. It certainly wasn't 4p a litre better, that's for sure.

Too true, dinkus.

I have seen people on this forum say they can notice the improvement.

Clearly, it can be measured with proper gauging equipment but I feel that anyone who says they can feel the car to be more responsive must either drive for 18 hours a day every day or - more likely - is happy to swallow the advertising blurb.

[Walesy 0]

I've never felt more power from higher octane fuel, just a less lumpy idol.

 

(( 10 hours average a day as a Joe Baxi driver , not quite 18 :wink: ))

[dinkus 10]

I think that if you've had the timing set up to make advantage of the extra octane, especially on the G60's with forced induction, then it can make a difference.

 

Otherwise, on a VR it seems a little pointless because the ECU won't adjust to make full use of the extra octane.

[ZippyVR6 0]

The only time I notice any difference between the high octane fuels and the supermarket stuff is on a cold start up, the drive is a little more smooth till warmed up with 98, after then no obvious increases in anything other than fuel bills.

[Wendy 0]

Have not read any of the above yet........

 

Annoyingly missed last nights show, have it recorded later as really wanted to see the 350Z report. I think these are fantastic cars, superb looks.

[joebloggsVR69 0]

The repeat is on in 3 minutes :wink:

[catch_twotwo 0]

Watching as we speak... need to know these sort of things ;)

[Ice White Socks 0]

Too true, dinkus.

I have seen people on this forum say they can notice the improvement.

Clearly, it can be measured with proper gauging equipment but I feel that anyone who says they can feel the car to be more responsive must either drive for 18 hours a day every day or - more likely - is happy to swallow the advertising blurb.

 

Maybe as lot of it depends on how you drive your car. A few years ago I worked in Durham and made a ritual of ragging home down A1 and M1 very late on a Friday night- very fast (but very safely..) and with more than a few races on the way. Always filled up with Fresh optimax before the run and believe me it *does* make a difference. Now I just pootle round town I still use optimax just from force of habit- But I can't tell any difference if I have to use '95 every now and again..

[craigowl 0]

Maybe as lot of it depends on how you drive your car. A few years ago I worked in Durham and made a ritual of ragging home down A1 and M1 very late on a Friday night- very fast (but very safely..) and with more than a few races on the way. Always filled up with Fresh optimax before the run and believe me it *does* make a difference. Now I just pootle round town I still use optimax just from force of habit- But I can't tell any difference if I have to use '95 every now and again..

 

Wont argue with you, sox. As you'll guess, I rarely go above 4500 rpm, old pootler that i am. :)

[polocarls 0]

Any one else think the woman presenter was a bit wimpish (i can say it cos i'm a layyydy) when she did the blind run that the blind guy had just done? I would of loved it, put the foot down all the way!!

[Ice White Socks 0]

Wont argue with you, sox. As you'll guess, I rarely go above 4500 rpm, old pootler that i am.

 

I was worried you might take it that way :-P

 

Its not often you get the opportunity to batter your car on empty roads and cold temps but that was one of them. Nowadays I don't have the opportunity so I don't take it over 4500 much myself now :) And like you say- in normal driving theres nothing in it between the two

[Andy T 0]

The G60 were set to run on 95 octane unleaded (hence the CAT) so will need a bit of a fiddle with the distributor to get the best out of 98 octance. All other rados would be set up for 95 octane

 

Nah.... the g60 was tuned for 98 Octane... and it says minimum 98 Octane on the inside of my fuel flap.

 

The CAT is only linked to 95 RON fuel because 98 four star was replaced by 95 RON unleaded (sneaky barstewards)

 

And fiddling with the dizzy on a g60 will do bugger all... they have a knock sensor.

[DelMonty 0]

I personally use Optimax for the cleaning properties, in the past I've heard a couple of horror stories from people using not very well known brands of petrol.

[craigowl 0]

delmonty said

I personally use Optimax for the cleaning properties

 

I tend to regard them as "alleged cleaning properties" unless someone out there can enlighten me in a convincing scientific manner.

One should never believe everything that someone says about the product they are selling, even if you want to.

[Sandy 0]

I've always ran my G60 on Optimax or Super for the the 8 years, I won't put normal unleaded anywhere near it. Anyway it only costs a couple of quid extra to fill the tank. Considering most folks spend lots on the C's does it defeat the purpose putting normal unleaded in the tank.

 

Remember you are what you eat

[bcstudent 0]

Well apparently the KR 16v would never run on unleaded, at least that was the story back in the day. Mine's never been touched and runs fine on the cheapest fuel I can get my hands on. I have to agree with craigowl, I'll believe it when I see it proven.

[Andy T 0]

When I first bought my old mk2 8v with 80k on the clock, the insides of the cylinders and back of the valves were pretty black, although the fuelling was spot on and plugs were clean. When Optimax came out I was using it 90% of the time. By the time I came to sell it fours years on at 122k, the pistons were very clean and the back of the valves were absolutely spotless!

 

The car had any never had any engine running problems, or fuelling/timing parts replaced in the time that I owned it, so its hard to say what cleaned it up other than the use of Optimax. Not very scientific I know, but I was surprised at the difference I saw.