Basic versus premium petrol - what are the facts

misterjingles

Thanks for all the replies ,just as a matter of interest is cleaning the EGR a simple (?) task .

vax2002

Higher octane fuel burns at a higher temperature, valves will wear higher, oil will be thinner and wear quicker and you might get an extra 1-5 bhp at 7000 rpm.

Premier_2

Don't buy premium fuels for standard cars



Many petrol stations sell ‘high performance' fuels, yet there’s little or no performance difference for most standard cars.

So for an easy saving, don't fill up with the super fuels unless you've a sports car that you've been advised will actually utilise the petrol correctly.

The AA's told us that for most, high performance fuels are too pricey for regular use. But if you're keen, it suggests using three tankfuls in a row to keep the engine clean and efficient, then revert to normal fuel.

http://www.moneysavingexpert.com/travel/car-check

Weird_Nev

vax2002 wrote: »

Higher octane fuel burns at a higher temperature, valves will wear higher, oil will be thinner and wear quicker and you might get an extra 1-5 bhp at 7000 rpm.

Absolute crap: Higher octane fuel burns at the SAME temperatures but gives significantly LOWER exhaust gas temperatures.

misterjingles wrote: »

Thanks for all the replies ,just as a matter of interest is cleaning the EGR a simple (?) task .

Depends very much on the vehicle, they can be tucked away down the back of an engine and very hard to get to. Actually cleaning them is pretty simple, you can use brake cleaner/WD40 or whatever solvent and a toothbrush to clean them off but the disassembly needed to actually ge tto them can mean it's a half day job.

alastairq

Where the difference in burn temperature may come from, concerns comparisons between 'modern' petrols, and fuels from 20 or 30 years ago, perhaps?

A problem owners of old cars/bikes etc, from before the late 1980's, is that the petrols around in those days burnt at lower temps.

Engines, and associated bits and bobs, were designed bearing that in mind.

Subject an engine from 50 years ago to modern fuel, with its higher burn temps, and new issues raise their ugly heads..[apart from those surrounding the use of lead-type chemicals to enhance octane levels...anti-knock, etc...]...........!

Apples2

misterjingles wrote: »

Thanks for all the replies ,just as a matter of interest is cleaning the EGR a simple (?) task .

Couple of links to read

http://zafiradiy.weebly.com/egr.html

This is what is looks like


Cleaning is simple enough, depends how gunked up it is.
1. Rag.
2. WD40 & Toothbrush
3. Brake/Carb Cleaner & Toothbrush
3. All of the above & flat bladed screwdriver
4. Caustic Soda
5. Blacksmiths Kiln/Blast Furnace

If you get to level 4, just buy a new one.

For the Code Reader, any old OBDII reader should suffice
Quick example but ask on Vauxhall forums to see what others have bought, they pay for themselves the first time you use it.
http://www.ebay.co.uk/itm/CAN-OBD-2-CODE-SCANNER-FOR-VAUXHALL-ZAFIRA-CORSA-COMBO-/330390341976?pt=UK_Diagnostic_Tools_Equipment&hash=item4ceccc8958

baby_frogmella

Apples2 wrote: »

The fuel is the same, the additives are different.
If I use supermarket fuel in my diesel, I add some millars diesel treatment.

+1 for the Millers diesel treatment, its fantastic stuff. For any doubters, have a look at the reviews:
http://reviews.halfords.com/4028/811125/reviews.htm
http://www.amazon.co.uk/gp/product/B002WCAISS/ref=pd_lpo_k2_dp_sr_1/276-5741538-4279434?pf_rd_m=A3P5ROKL5A1OLE&pf_rd_s=lpo-top-stripe&pf_rd_r=1J8VV20Z6Y8Y1JVNMWBH&pf_rd_t=201&pf_rd_p=103612307&pf_rd_i=B003IJVH9S

Rover_Driver

A lot depends on what the OP's mechanic meant by 'basic' - supermarket petrol doesn't have the additives that the main retailers add which may help keep the EGR a bit cleaner, or their premium petrol as against their super.

cardinalbiggles

Rover_Driver wrote: »

supermarket petrol doesn't have the additives that the main retailers add which may help keep the EGR a bit cleaner

Sorry but that is downright misleading. Supermarket fuels all have additives in them. The main retailers *want* you to think you are getting something extra, this is what's called marketing. Sure the additives may be different but they don't make much difference to your average driver and they certainly don't increase fuel economy.

misterjingles

cardinalbiggles wrote: »

Sorry but that is downright misleading. Supermarket fuels all have additives in them. The main retailers *want* you to think you are getting something extra, this is what's called marketing. Sure the additives may be different but they don't make much difference to your average driver and they certainly don't increase fuel economy.

Thanks for all the feedback - don't want this thread to overcook with too much opinion. Just to say that my mechanic , who is a quite decent bloke, is a firm believer that there are good & bad quality petrols . This may be an urban myth - but it's what he believes.