Fully-synthetic engine oil

[Gromit]

Morning Trixters.

Haven't covered this for a while - what's the general consensus on this stuff? We all know how synthetic tranny oil helps the bike no end but who on here actually uses fully synth engine oil?

It's just that every now and again, Halfords have a bike oil discount which means really big savings on the stuff - seeing as their lubricants are made by Castrol (which I have on reasonably good authority) it'll be good gear. 20 quid or so for 5 litres of fully synthetic motor oil has to be bloody good value.

What mileage to stick it in though? Mine, on 12k's probably early days yet but worth bearing in mind for its mid-service oil change at 15k.

[Skint]

Gromit,

Have used fully synth, but could not give you an honest on it, i just buy the cheapest and bang it in. The bike is at 73K so will not suffer som synth but i change the oil every 3 months so would not notice any long running issues where the oil is sitting and get temp extremes. But having said all that it seemed to run the same to me..

[crucial]

I don't know if you have a Costco near you, but they do Mobil 1 for about £23 for 4ltr

[Gromit]

Thanks - dare say I'm quite interested in the smoothness the motor might gain (if any!) by using such oil. Always felt though that it's not what oil's used so much as how often it's changed.

In the days of riding CBR6's and the like I'd use fully synth as a matter of course - the bike was caned on a regular basis - but using it didn't save my 1000Exup as that threw a rod at 10000rpm. Lots of Pro4 all over the A413.

[Gromit]

I don't know if you have a Costco near you, but they do Mobil 1 for about £23 for 4ltr

For the bike oil??

That's cheap! Thanks for the tip - there's a Costco in Watford, I'll borrow the card off one of the guys at work.

When we go to France we get Mobil 1 Diesel oil for the Citroen - equivalent of 18 quid for 4 litres (or was a year or so ago). Rip-off Britain? Of course not

[Skint]

Thinking 'bout it, have a buzz with the local aouot suppliers, you can use some of the auto brands if you change the ois frequently..
I found some home brand stuff which was being sold as £5 per litre of semi, the home brand was supplied by Vauxhall, which is manned by Castrol or Shell, the cheapest at the time.. If you can store a 25Ltr drum, you will be best positioned to buy one as they are well cheap in the long run...

[Skint]

Do you really need bike oil gromit???
I've been using car stuff in the S eversince i got the thing... As its a high torque, you can bang in the 'ol car oil.. much cheaper and you can find better deals...

[Gromit]

Do you really need bike oil gromit???
I've been using car stuff in the S eversince i got the thing... As its a high torque, you can bang in the 'ol car oil.. much cheaper and you can find better deals...

It's a moot point - I once put some Mobil 1 car oil in my old R1100R, the bike had done 25k-ish miles so was well run-in. It ran very well although seemed to consume more of this oil than it did with semi. I'm wondering if the 'slippier' Mobil 1 was getting past the rings? Just a thought.

[Skint]

It's a moot point - I once put some Mobil 1 car oil in my old R1100R, the bike had done 25k-ish miles so was well run-in. It ran very well although seemed to consume more of this oil than it did with semi. I'm wondering if the 'slippier' Mobil 1 was getting past the rings? Just a thought.

I dunno, been using some Vauxhall semi 10/40 at the moment, no oil loss at all.. I just ring around suppliers and get a job lot, i think it was 30 litres for about 20 quid.. The 75/90 or 80/90 gear box at 1-2 quid 500ml. I then use the Active 8 junk as additional to the oils, as i can't confirm who the original manuf was.. It saves a packed compared to halfords and the rest... But there is a seal gon some where at the mo, or i keep overfilling the engine, as the block has oil weep all over it... ooh well time for a rebuild anyhoo..[/quote]

[stempy]

I've been using Castrol RS1 car oil in mine with no probs, and no leaky seals as yet.

[Jason M]

Didn't I read something in one of the mags recently saying that boxers only liked mineral oil - dunno where they got that from.

I use Quantum (about £10-12 for semi synthetic 5 ltr through German and Swedish) and find that is uses a fair bit when first changed then hardly any when it's nearing the next change. Much of what it uses comes straight out the pipes when I start up - never leave it on the sidestand for very long now otherwise there would be a cloud you could see from space when I started it.

I personally don't think expensive oil is worth all that extra cash - like Richard says, there are only a very small number of manufacturers and a lot of rebranding going on so you're probably getting the same as the bloke forking out the extra anyway half the time. Maybe it would be different if the engine revved to 20000, but I don't go above 6.5 most of the time so it's not exactly overworked

Jason

[Gromit]

Jason - I think you've pretty much hit the nail on the head. Also, it's interesting how a full page flashy advert in a bike mag may have a large influence on folks' buying habits. I know it has me in the past - 'Our oil will give an extra 5% power etc etc'.

I dare say the fully synth might be good for guys who don't use their bikes on a regular basis due to its possible benefits on cold start ie an engine which gets to sit for a period of time will need all the help it can get when taken out for a thrash.

I have heard (may have been from Plankton Pete when he had his new S) that new Boxers are filled with straight 30w for the first 600-1000 miles, for running in. I wonder if the motors would benefit, in the long term, from changing to the same at 500 then going onto semi at say 2000? Having said that, the engines on these bikes seem to be nigh on bulletproof - it's more likely to be tranny problems which rear their ugly heads.

[RiceBurner]

Grom - I think most bikes are filled with straight mineral oil for running in - fully synth is TOO good for running in and you NEED some friction to get the bores and rings mated nicely.

This is a question I've been meaning to ask actually - I've been running wet-clutch bikes for the last 10 years, and using semi- or fully-synth (Silkolene Pro4 and Pro4+ for preference), but the boxers are a dry clutch aren't they??

so what's the best oil - fully? semi? straight mineral???? Is it ok to use regular oil such as Clistrol GTX?

and what oil goes in the gearbox and bevel box?

[Gromit]

RB - on the whole, any bike 4T oil will work fine be it semi or fully synthetic. I'm only too aware of the problems caused by 'running in' a motor on fully synthetic - in the days of owning a Caterham 7, one guy in the club ran his brand new K-series motor in on Mobil 1. After 10k it had huge oil consumption - the engine's bearings had glazed (I think that's what the engineer said - it was f*cked anyway).

As to the tranny - a good quality 75w90 gearbox oil, then stick fully synthetic gearbox oil in at the 6k service. It makes a hell of a difference.

[carlk]

I buy the castrol magnatec stuff
I used to stick the deisel version in the ole M2 and it were good in that too