Total Excellium vs standard unleaded

snipped-for-privacy@DENTURESsussex.ac.uk gurgled happily, sounding much like they were saying:

In a car like yours? None whatsoever.

If the car has a base ignition map set up for 98 octane, with a knock sensor to pull the timing (or boost on a turbo) back to suit 95, then - yes, it may very well make a sufficient difference. The majority of "cooking" cars won't have.

Experts say they are a waste of money with the proviso that an older or higher mileage car may benefit from the "cleaning" effect from the superfuels - Shell and BP also do them too.

Having said that I've a CRV petrol auto with an average MPG display - I'm pretty sure that when I use BP ultimate I get around a 2mpg improvement from around 26 to 28 per tank - nothing scientific but as I fill up once a week and my weekly trips are pretty similar ...

A friend also uses Shell Ultimate diesel ocasionally as he was advised to by his garage (after having a few running issues) Its a newish 320 diesel clk and admitting it runs "better" with it being a cheapskate he alternates :)

During the summer, I tried several tankfuls of "super" grade petrol in my Focus, (although not the Tesco one). I was unable to find any good reason to continue to use it.

Chris

Thus spake my good self unto the assembled multitudes:

Thanks all, the consensus seems to be that it's a waste of time and money, so I guess I'll be sticking with the standard unleaded. I already get upwards of 40mpg out of my Astra (best ever was 46mpg), which after all ain't bad for a 1.6 litre petrol engine.

I don't know if your engine can compensate for the higher octane rating. The additional additives may improve matters, but it's hard to distinguish between higher octane and better detergents.

The Saab turbo performs better on it. I don't have enough data to statistically confirm if the small consumption reduction is genuine or luck at the moment.

This is a '04 9-3 1.8t, showing 39 to the gallon since I bought her *grabs PDA* but this is broken down to:

But don't get excited, because 0.5 mpg is *way* too close to be statistically significant. This is only over 1,200 litres (just over half being 95 RON).

You need to get out more (not in the car)

Mrcheerful

LOL!

Unusually for me, I didn't go out of my way to track these figures. I use TealAuto on my Palm to track expenses and mileage and was putting brand / octane / type / meh into it "just because." Then with a previous release, the developer integrated the reporting features, giving me access to all sorts of useful and useless information.

Don't they state on the pump that if you don't see any benefit, you get a refund? Not sure how they administer that though.

Thus spake Mrcheerful ( snipped-for-privacy@hotmail.com) unto the assembled multitudes:

So should I. I've been recording fuel stats on both the Astras I've owned, since 1992. Cor, you oughta see the size of my Excel spreadsheets :-)

Thus spake Mark W (s@o) unto the assembled multitudes:

Yes, I seem to recall that they do. Sounds like a useful wheeze to get a free tankful of fuel ;-)

In article , snipped-for-privacy@DENTURESsussex.ac.uk writes

Since 1981 here, (all on Excel now), with ghastly-looking graphs for the price of fuel.

Roger Hunt gurgled happily, sounding much like they were saying:

Any chance you could share those graphs...?

Be interesting to compare them to the RPI and CPI.

In article , Adrian writes

Could do. I should add that between '91 and '97 I was without car, and never kept motorcycle fuel figures because I'm forever draining fuel to clean something or other so the figures would be meaningless.

Same here, other than the fuel cost. Every tank of fuel and mpg recorded and graphed since 1983 and some data for the motorbikes before that from 1978 onwards but not entered into a spreadsheet. I think we must be too anally retentive or summat.

One thing I have noticed is that despite all the cost and complexity of modern FI systems and emission controls to supposedly improve mpg the average mpg of similar cars I've owned hasn't changed a jot in 25 years. The engine efficiency might have gone up a tad but the car weight has also increased to compensate due to safety laws. The net effect is near as dammit zero. We've basically just paid a lot of money out to try and prove how green we are but none of it has actually had any effect. The most fuel efficient cars I've owned have been small ones with small engines and with carbs. It's hard to beat an SU.

Peugeot 106 XND?

In article , Dave Baker writes (snip)

Absolutely agree. Most of my driving is local stop/start, and the fuel consumption mostly goes on getting the vehicle into motion. Once I'm on a smooth long journey the consumption plummets.

Yea - what one loses in acceleration and top speed, one gains in other areas.

Thus spake Dave Baker ( snipped-for-privacy@null.com) unto the assembled multitudes:

OK, now that we geeks are coming out of the closet and sharing this affliction...

I also record other expenses such as servicing, repairs, consumables, and tax, and with a 'current market value' stored (updated year by year), together with price originally paid, obtain an overall cost-per-mile figure. I'm not entirely sure whether or not my method is flawed, but currently it stands at about 23p per mile.

I also have an identical spreadsheet for my motorcycle... which costs more per mile to run than the car :-(

snipped-for-privacy@DENTURESsussex.ac.uk gurgled happily, sounding much like they were saying:

I don't. If I did, it's unclear whether I'd kill myself before 'erself killed me or not.