http://www.therange.co.uk are selling Unipart 5w-40 full synth 5 litre pack for £18. SM / B3/B4 spec. Not on there website though.

£18 seems quite expensive.

Why does engine oil cost more per litre than diesel, when diesel price is mostly tax?

There was a letter in Diesel Car magazine, Feb 2005, issue 203. (www.dieselcar.com)

" Myself and two other motoring enthusiasts got together to find a cheaper way of getting quality oil at a better price. We each agreed to accept a 20 litre container and, armed with an order for our 60 litres. I went to a local oil distributor to get a price for some fully synthetic oil in this case Total Quartz 9000 5w/40. In January 2004 I was quoted £1.45 per litre including vat. When we eventually went to order in October we had expected a price rise – what with the escalating cost of crude oil. We were then quoted £1.20 per litre, plus vat and I could barely believe it! I was told that it was because the order was placed at the beginning of the month! That worked out at £7.05 for 5 litres, delivered to my front door. Apparently we were classed as "bulk-buyers"."

£18 isn't too bad for fully synth. Just a note, B grade oils are for diesels.

silkolene pro-s 5w40 fully synthetic = £10/litre so thats not bad at all.

on a slightly different note………..

If your doing DIY oil changes, and doing them regularly then mineral oil is just as good as synthetic. Synthetic is good for 12000mile service intervals, mineral oil is perfectly adequate for 3000 and 6000 mile intervals.

The only downside is its often a lower spec and as modern engines run with smaller sumps to get more power and thus need the additives found in better (often synthetic) oil. But if your car is older and doesnt need the latest/greatest additive, ASDA sell SAE 20/50 for about £1.60 a gallon!

http://www.carbibles.com/engineoil_bible.html

Problem is my filter costs £12(Fram) £17 Nissan so longer intervals between changes is better for me. Also in theory a 5w synth is better than a 10w mineral/part for fuel economy.

Just buy the stuff in 25 litre containers, split it with your mates if needs be. Or go to the local motor factors and haggle a bit. As per the story above, I generally get oil meeting VW spec (not the fully synth stuff mind) for approx £1 a litre when buying 25L at a time, and that's from the factors, not the oil firm. For what it's worth, that oil is above minimum spec for my 20 year old Golf and my girlfriends' 12 year old golf.

I really wouldn't run cheap oil in any car on the basis that you change it more often – by the time you account for a new sump plug, filter, washer & your time emptying the sump, refilling it and taking the oil to the tip, you've saved tuppence and risked your engine's health. The Asda 20w50 would be below spec for my 20 year old Golf, and probably anything short of a Morris Minor…

There was a report from one of the car websites – that eludes me right now
Anyway the upshot was they claimed that reducing the oil change frequency by 33% & increasing the filter change frequency by a similar amount was the way to go to get the best value out of it without increasing engine wear etc.

i.e.
oil change every 8k
filter change every 16k
instead of both every 12k

I've heard good (adequate) things about Asda 20w50 for minis…

To be honest, when you look at the reason cars get scrapped these days, you're very rarely looking at dead engines except in the case of folk who do without oil changes & checkign the dipstick. More often than not, the car's rusted away, the interior's ruined, or some component or another has failed that's not worth replacing.

Last car I sent to the scrappy was one I'd bought for £225, and had a dead power steering pump. Still ran fine, but the whole package was so rough that there was no way anyone would consider buying it off me and repairing it.

I've heard good (adequate) things about Asda 20w50 for minis…

The ones that use 50 year old engine designs? 😆

To be honest, when you look at the reason cars get scrapped these days, you're very rarely looking at dead engines except in the case of folk who do without oil changes & checkign the dipstick. More often than not, the car's rusted away, the interior's ruined, or some component or another has failed that's not worth replacing.

I agree but the car does run a lot better when it has fresh oil in it. And i want to keep the turbo happy as that is probably the weak point in the engine. 97 reg on 170,000 miles is not too bad.

I bought 25 litres of this for £64.75, around £13 per 5 litres.

Synthetic is good for 12000mile service intervals, mineral oil is perfectly adequate for 3000 and 6000

Sounds like a good reason to use fully synth to me!

my point was some cars (minis, minors, midgets) need an oil change every 3000miles, so saving 90% on the oil price is pretty good, itd have to last 90,000+ miles to be worth running synth oil assuming it breaks down tomorrow on mineral.