Jump to content

Premium petrol/diesel - any difference?


aris
 Share

Recommended Posts

  • Replies 112
  • Created
  • Last Reply

Top Posters In This Topic

As a follow-on to this - does anyone use any additives in their fuel? I have heard that Millers Diesel Power can give noticable improvements - similar to what people see with premium fuel (less smoke, more power/acceleration, better economy), at less cost. Just add 1ml per L of diesel at every fill-up. That roughly comes to about a pound per fill-up.

 

I used Millers Diesel Power Eco Max before I did a 270mile round trip. The instructions stated that it could take 200 miles approx before any significant difference could be noted. On my return trip, and almost on 240 miles, I will say that my engine did sound quieter and acceleration was slightly improved. I'm waiting until my fuel warning light comes on, and then will fill my vehicle up again, and add another shot of Millers. As I mentioned before, using Millers works out at approx 2.6p per ltr.

Link to comment
Share on other sites

Just an update as promised,

 

Tank 5 did 480 on the nail

 

Tank 6 did 471.

 

I think the 480 is a more realistic figure as it was a normal work week and lots of stop starts ,motorways a and b roads,the 490 was a straight run up and down the country.

The 471 will have to take into account a fair bit of offroad yesterday round a lot of my permissions.

 

Engine still sounding good and pick up is great.

 

So far averaging just over 468mpg for the 6 tanks,so two more tanks and see how it's going

Link to comment
Share on other sites

Ive started mixing two stroke at 150:1 after reading all the benefits. What ratio do you use?

 

Not to jump in on someone else's answer , I've used 2 stroke oil in my terrano since I've had it

I use 100ml to every 30 litres of diesel , I very small increase in economy, but the main thing a lot quieter I find :)

Link to comment
Share on other sites

My 07 plate VW Jetta 2.0 TDI runs like a bag of bent spanners on supermarket diesel so i run it mainly on Shells Fuel saver diesel and its a lot smoother and i can get around 52 -55 mpg out of it which drops to around 49 mpg if its only driven around town but if i put the Shell super diesel in it makes a huge difference to performance and when driven sensibly on a run the mpg is 60-62 so not having done the maths i do wonder if i would not be better off just running it on the super fizzy shell premium diesel all the time?

 

one theory i have on the "premium" or "super" fuels is that they are not actually messed with to any extent but are merely pure petrol or diesel ie with less bio diesel mixed with them? as i have been told thats the reason supermarket fuels are so bad due to the higher bio fuel content which is what makes it cheaper? which i think is a false economy as i know lots of people who had serious engine failures through super market fuel problems

 

on a lighter note my wife found out not long after i got my Jetta that it really really does not like shell or any other brand of petrol!!! :/

Link to comment
Share on other sites

It's actually the oppisate beeredup, good pertrol or oil/hydralic oil etc actually has less petrol/desiel/oil in them than cheaper brands, but more additives and it's the additives that are expensive but also make the fuel/oil perform better.

And yes there is a larger and larger % of biofuel in supermarket stuff nowadays.

 

My brother ended up running/looking after a small perol station for a while, it was always a penny or 2 dearer than the supermarket one at other end off town but all the 'carboys' used to get there petrol there for there fancy performance cars, even thou they were skint, ie only putting £5 or 10 quid in at a time, probably all the money costing them for insurance.

Also his wife thought he had done something to his car or had it tuned as even she noticed the performance gettin better (lexus) and that was just with normal quality petrol over supermarket stuff.

 

Dunno if many off u can mind there was a load off problems down south/london area, possibly 10ish year ago with cars just conking out all over the place, its was meant to be some bad batches off petrol in supermarkets that had somehow got containated with silicon, the additives in a normal brand (ie non supermarket) would probably have masked it and the problem wouldn't have happened

Link to comment
Share on other sites

Only ever noticed a real difference with the good stuff when I have a turbo, it is very noticeable then. Even with a n/a car there is s difference but most won't notice.

I think top gear did a show on this and the turbos were 20bhp up on the good stuff but normal cars didn't change.

Edited by GingerCat
Link to comment
Share on other sites

I recently put unleaded in my diesel :no:. i put in 10 litres or so then topped with 50 litres diesel not by choice mind, anyhow the car didnt like it at all it would start then konk out smoke like hell sometimes then cut out while driving i persevered this way for about a week keeping topped up with diesel now the car runs fine no problem at all i think i am even getting more to the gallon than before.could this be right??

 

 

I'm thinking the petrol cleared up your diesel injectors :)

 

I wonder if using 3 or 4 tankfulls of premium diesel would be a good idea just before your MOT - particularly in older cars.

 

When I first started study biochemistry (microbiology) a guy gave a demonstration of microbial contamination of fuel. He took the three most commercial important liquid fuels (petrol, diesel and kerosene) put them in flasks added about 10 % tapwater, shook 'em and and left them in the dark for a week. Both the kerosene and diesel samples showed extensive fungal (pronounced with a soft 'g') growth (kerosene had by far the greatest). Petrol had none: he said that this because petrol contained quite a lot of short chain hydrocarbons (light fractions) that poisoned/inhibited microbial growth. He showed this work to a major airline who immediately gave him a very 'juicy' consultancy.

 

These results would suggest that the 'build up' formed in diesels isn't the result of 'duff' fuel but 'normal' microbial contamination caused by the fuel sitting around in storage for very long periods. I would also assume that all of the additives added to diesel are there to remove the microbes in your tank (nice warm storage vessel that's frequently agitated) as well as surfactants (the proper word for detergents) to remove the combustion products of these. The petrol was probably a very expensive way of doing the same thing.

Link to comment
Share on other sites

DrBlox,

 

That is very interesting. That would suggest to me that firstly, go to a busy petrol station (fresher fuel), and secondly, the additives in diesel may well make a big difference.

 

The Premium Shell Diesel is apparently made up partly from GTL - which is essentially a synthetic diesel fuel. I wonder if this is less susceptible to fungal growth.

Link to comment
Share on other sites

After adding the first 'shot' of Millers Power Eco Max, my vehicle returned 36mpg, which was measured over a distance of 345 miles. The first 240 miles were on motorways/dual carriage ways, which recorded 39mpg. The remaining mileage was around town, up and down hills with a lot of stopping and starting. This reduced it to 36mpg. I have just put 50 ltrs of diesel in the tank and added another 'shot' of Millers. All my driving will now be around town again, with many short trips etc. I'll check the reading again when I'm due to fill up again.

 

Link to comment
Share on other sites

... That would suggest to me that firstly, go to a busy petrol station (fresher fuel)...

 

Errrm dunno. I'm assuming the diesel is 'made' at the refinery. Is it stored 'on-site' at the refinery for a while? It will then be transported to a storage depot - I believe the 'hygiene' here would be poor. The transport tankers would be used for a variety of hydrocarbons - perhaps the flushing/filling with petrol 'sterilises' the tanker. Before being delivered to the petrol station where it sits for a 'long while' in filthy conditions. Anyone ITK on how often the storage tanks are cleaned?

 

I would reckon that the biggest source of contamination would be your car's fuel tank - frequent exposure to air (and all those fungal spores), limitless supply of food, plenty of agitation so an optimum mixture is formed and it's nice and warm.

 

Also, I've always thought "What use is there in burning a surfactant?". I can see them 'cleaning' fuel lines but once they're burnt there just extra energy.

 

Bear in mind I work in biomaterials not hydrocarbons - this could all be cobblers.

Edited by DrBlox
Link to comment
Share on other sites

I believe fuel at storage depots are cleared pretty quickly. The biggest volume of fuel in the uk is the collective volume in all our petrol tanks. As for petrol station tanks - I wonder if they are ever cleaned. They do seem to replace the tanks every 10 years or so though. Petrol pumps do have filters on them.

Link to comment
Share on other sites

  • 4 weeks later...

I'm not sure if anyone has noticed, but Shell are quite pricey these days. They used to be on a par or cheaper than anyone around for regular petrol or diesel, but now are up to 6p more expensive. The premium Diesel is 8p on top of that.

 

My local shell do regular diesel for 138.9 - local Esso is 132.9 - BP 134.9

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...