What is acceptable oil consumption?

[idl1975]

My understanding of the theory is that a top grade, high-viscosity synthetic should be better because it is "thin" to achieve best possible coverage, especially in cold conditions, but has a high purity (long chain esters) base stock combined with the latest and greatest in additive packages, the latter giving the oil a very high shear resistance.

That is supposed to mean (a) higher film strength, i.e. the thin film of oil can't be "squeezed" away from the lubricated surfaces as easily, so even if you have a thinner film (and it sounds noisier), you have equivalent or greater protection, and (b) because of the purity of the base stock and the nature of the additives, shear resistance is maintained for longer. This last should allow you to use extended oil change intervals, as the oil will last longer before contamination/breakdown of the oil reduces film strength.

There are many boring sites on the web, mostly by Americans (some of whom drive many many miles, remember), with both lots of opinions and theories on oil, and actual oil analysis. One I recall using an LS1 engine as an example and the Blackstone labs oil analysis service basically suggested that the main benefit of fully synth was an extended service life. Fully sythetic went for about 2x the mileage or greater before significant breakdown products showed up in the analysis, suggesting the oil was "tired" (breakdown and "burning" of the oil, byproducts from reactions with contaminants in the base stock and wear materials, etc.).

Interestingly, this random internet dude's analysis (and some others I've seen) suggested that most of contamination indicative of direct wear to rings and bearings (as opposed to breakdown products from the oil itself) occurred within 500 miles of each oil change, following which it stabilised until the oil started to "wear out" (5k miles semi-synth, 10k+ for a full synthetic). Yes, 500. What that SUGGESTED was that you MAY actually cause more issues by changing the oil very frequently than by choosing an appropriate grade and leaving it for a "safe" number of miles (i.e. before it starts to breakdown and lose effectiveness).

Ah, speaking about oil, I just read this in the Haynes manual (aka the great book of lies):

Oil type: API grade SE, SF or SG
Oil viscosity: SAE 10W30 or 10W40

Caution: Yamaha advies against using chemical oil additives, or oils with a grade of SH/CD or higher, or oils labelled ENERGY CONSERVING II. Such additives or oils could cause clutch slip.

after spending a small fortune on Castrol power RS (10W40) with API grade SJ.
So that would be too good in quality! I just put the oil in, because I don't think the cluth will slip.
But will "thin" oil with a low (or is it high...) level of viscosity result in higher oil consumption?

[phuk72]

What that SUGGESTED was that you MAY actually cause more issues by changing the oil very frequently than by choosing an appropriate grade and leaving it for a "safe" number of miles (i.e. before it starts to breakdown and lose effectiveness).

A suggestion universally ignored by race teams throughout the world

[idl1975]

What that SUGGESTED was that you MAY actually cause more issues by changing the oil very frequently than by choosing an appropriate grade and leaving it for a "safe" number of miles (i.e. before it starts to breakdown and lose effectiveness).

A suggestion universally ignored by race teams throughout the world

...who rebuild their engines regularly.

Obviously, although there are many reasons why changing the oil could increase wear temporarily (lack of oil/oil pressure until the new oil gets circulated out of the sump/tank being the obvious candidate), there are as many theories which could explain the opposite. For example, that wear metals get retained in the old oil and sludge and then leach out of the retained oil/sludge first when you fill with fresh oil, so these tend to show up as apparent "wear" soon after each oil change.

Basic point is, a top-of-the-line fully synthetic may offer more protection (shear resistance) and offer it for longer than a mineral or mixed base stock, even if you run a lighter "cold" weight (for coverage/penetration), and this means higher-pitched whirring and banging from "down below" (the engine not the rider! )

Realistically, it will probably make no difference unless one is trying to go three times round the clock on one's TRX. Most engines will never do enough hours before they're smashed into a lorry/pit wall, retired or the bike is scrapped to find out. Those that do are likely to need a rebuild for reasons wholly or partly unrelated to what oil was used.

[steve speed]

i love oil thread's don't you

[idl1975]

i love oil thread's don't you

You won't want to read this then

It's the LS1 site where they've been spending £££ (or $$$$, at current exchange rates) analysing oil samples to try to find out about the performance of modern synthetics. They did Mobil 1 and Amsoil, and were able to run the Mobil out to 18,000 miles (!).

http://neptune.spacebears.com/cars/stor ... -life.html

Amongst other claims:

"Engine wear actually decreases as oil ages. This has also been substantiated in testing conducted by Ford Motor Co. and ConocoPhillips, and reported in SAE Technical Paper 2003-01-3119. What this means is that compulsive oil changers are actually causing more engine wear than the people who let their engine's oil get some age on it."

"While the wear metals all accumulated steadily over the course of the test, the highest concentrations of accumulation per mile occurred in the first 3,000 miles of the test! From the 3,000-mile mark all the way to 18,000 miles, only lead showed an increase in per-mile wear beyond 3,000 miles. Yet even with an increased wear rate, lead wore the least in terms of absolute wear. For iron and copper, the longer the oil remained in service, the lower the wear rate got.

In case it isn't obvious yet, this means that the most wear occurs in the first 3,000 miles."

I'm absolutely not endorsing or criticising the above statements, lest the flaming begin. No idea how accurate or applicable it is, but it's something to consider.

Also interesting if you look at the Mobil test page, the suggestion that the LS1's frequent top-ups (it's a bit of a drinker, sort of like SOME or many TRXs) make a huge difference to oil life. Perhaps that's an up-side to the total-loss lubrication system on my TRX?

[Kayla]

Perhaps that's an up-side to the total-loss lubrication system on my TRX?

The TRX is the two-strokest four stroke I've owned, my old fiesta notwithstanding as that used to actually leak.

[idl1975]

Perhaps that's an up-side to the total-loss lubrication system on my TRX?

The TRX is the two-strokest four stroke I've owned, my old fiesta notwithstanding as that used to actually leak.

Do you think I could just run premix? I could remove the oil tank completely then.

[Mincehead]

Hmmmmmm,I`m a tad sceptical at the authenticity and accuracy of many of the oil claims in general to be honest.
There`s many an industry psychoselling it`s wares I can assure you all.
In nearly sixty years of motorcycle ownership by my father and straight Castrol oils mostly,he never encountered anything but normal wear and only one engine failure from a valve breaking due to his over exuberent right hand and a broken Smiths rev counter.
I myself have nigh on forty years of biking under my now `tighter` belt and apart from a chip out of a valve head and a cam chain breaking and trashing a crankcase it`s been nothing but quite normal wear that I`ve experienced too.
Anyway,my ten-pennuth:

1) New oils with fresh detergents will likely strip `stubborn`contaminants from bearings,inner case walls,oil galleries etc that will indeed give elevated readings and of course circulate more within the fresh oil.
2) There`s also contamination from blow by that causes higher petroleum distillates(petrol)to allow evaporation of more of the base oil,when oil is fresh and thinner this may indeed increase the levels of contaminants too.
3) If you consider the top two may have some merit,then yes,fresh oil or oil changed too frequently could indeed increase engine component wear rates.
4) Something else to bear in mind that I`ve just added/edited in.
Oil contamination with softer materials can indeed provide`cushioning` for areas that experience a particularly hard time like gearbox selectors,clutches and the like.When I say cushioning I mean that micro ground softer metals like phosphor bronze alloys and even normal zinc/aluminium alloys can give a cushioning effect when they are present and suspended in the oil.
It`s the harder,mostly ferrous metals that`ll do the damage as they circulate,hence the idea of magnets in sump plugs and magnetised caps on oil filters.
Racing bikes are regularly stripped so as has already been said they`re not likely to show wear rates that compare to bikes used on the road anyway,it`s mostly breakages that they encounter through extreme stresses.
Quality oils have stood the test of time,we all know the classic brands and often `new` doesn`t mean better.
I run a synthetic(halfords)in my tuned Skorpion(XTZ/SZR 660 motor)but a good semi-synthetic or even quality multigrade will easily suffice for the standard and understressed TRX/TDM motor.
My old 78 SR 500 which is bored to 537cc and running a Wiseco 12 to 1 ratio runs best,coolest and sweetest on Castrol GTX 20/50 a damn good oil that has stood the test of time.I do however coat my camshaft lobes and follower faces with a molybdenum disulphide spray coating `Molykote` to offer some additional wear resistance to recognised high wear areas.
SR`s are famed for cam and follower wear.

[cameronjung]

n00b here...short story so apologies....

following everyone's advice i have been watching my oil level like a hawk and thankfully so - ive done around 1000km in the couple of weeks i've owned it and i've filled it from min to max twice.
I'm constantly looking in my mirrors and listening intently for the telltale signs of engine death but apart from the engine whine there's bugger all to write home about.

So...

Today i was shopping for a LAMS bike for a friend of mine who is just starting to learn to ride and the first thing the shop owner asked when i approached him was, "hey did you just roll in on a trx, i thought i heard one?"

Bit of talking took place and i mention my bike's insatiable appetite for lubricants. I barely finished my sentence and he tells me to stop using synthetics.
Ive never had anyone tell me to NOT use synthetics before.
He was of the opinion that big bore two cylinder bikes don't like it. He claims to have had terrible trouble with a TRX not long back and all was good once he went back to mineral oil.

Do i submit to this craziness or is this guy trying to kill my bike?
Remember, i do have 91,000km on my TRX...

Thanks guys

[Mincehead]

A `drinker` won`t be in the least compromised by using a cheap multigrade 10w40, there`s plenty that meet API specifications.
Alternatively do as I do and use a semi-synthetic 10w40, I use Halfords own brand, nice and cheap when you have a trade account.

[Kevtrx849]

+1 Semi synth is the way to go. I use Penrite and i have over 130,000kms on my bike with no oil consumption between changes.
Touch wood

[M.V.]

n00b here...short story so apologies....

following everyone's advice i have been watching my oil level like a hawk and thankfully so - ive done around 1000km in the couple of weeks i've owned it and i've filled it from min to max twice.
I'm constantly looking in my mirrors and listening intently for the telltale signs of engine death but apart from the engine whine there's bugger all to write home about.

So...

Today i was shopping for a LAMS bike for a friend of mine who is just starting to learn to ride and the first thing the shop owner asked when i approached him was, "hey did you just roll in on a trx, i thought i heard one?"

Bit of talking took place and i mention my bike's insatiable appetite for lubricants. I barely finished my sentence and he tells me to stop using synthetics.
Ive never had anyone tell me to NOT use synthetics before.
He was of the opinion that big bore two cylinder bikes don't like it. He claims to have had terrible trouble with a TRX not long back and all was good once he went back to mineral oil.

Do i submit to this craziness or is this guy trying to kill my bike?
Remember, i do have 91,000km on my TRX...

Thanks guys

I wouldn't be too worried about it, as long as there's enough oil in the bike to keep oil pressure.

I'm about the switch to Delo400, a mulitgrade fleet/diesel oil that is supposed to be great for bikes... We'll see how that goes, I guess.

[dfh]

since my engine rebuild , 878cc kit and valve stem seals plus a big clean up of all the engine internals,, i have now done 650 miles,, mine uses NON so far , and i honestly think it was more to do with stem seals than anything else , i am still on a Mobil 15/40 mineral oil

Stem seals are the key Steve Speed... after my top end refresh - new valves, stem seals, rings, head cleaned up oil consumption dropped to zero. After another 10,000km oil consumption back to what I was used too before the work as the seals age. You will experience the same. The Popes a catholic, the sun sets in the west, TRX's use oil.

[cameronjung]

Thanks guys

[olivernz]

Hi all,

Well, mine started eating oil(probably always did). No idea where it originally came from but I was on Q8 Semi Synth and didn't notice much. Then went to Motul Semi and that was just shocking. Then used Castrol GPS for the last few fills. So now it's at about 800ml on a 1000k's when I ride it fast. Commuting is noticeably less than that (although it has highway 100km/h on that route too). Has 51k down.

I got a compression check done yesterday and that was a-ok (175L,180R). I have no smoke when started at cold or while riding. Can't smell oil either (and the bike behind can't either).

I've now decided to go to a mineral oil on the upcoming change and see if that makes a diff.

Cheers Oliver