During a recent ride the oil light indicator came on the Speed Twin 900. In a panic I stopped in a the nearest town to find some oil to top up. The only place being a local garage. They didn't have motorcycle specific oil but some car petrol engine SAE 10W/40 which I then used to top up the engine. The 'normal' oil used in the engine has been Castrol Power 1Racing 4T 10W-40 (fully synthetic) as specified in the handbook. Will this mix of oils be a problem? The bike has done 1200 miles. Should I be looking to do an oil change?
If it was me I would also change the filter but I can't see it being a problem if you empty out the old oil and flush the filter through with the new stuff. The other question is why it was low on oil at such a low mileage? How much oil did it actually need to top it up? Don't forget the drain plug needs a new washer as well and if you do re-use the filter check that the rubber seal is intact and undamaged.
As has been mentioned, some car oils contain additives that can cause clutch slip. In addition, bike specific oils are also formulated to work in a gearbox with the shearing forces that places on an oil. That's what the oil tech guys say. Having said that, a minor top up wouldn't bother me personally. An old biking friend of mine bought a slightly used GPZ900R in 1985 and ran it on Unipart 10w/40 car oil, from his local car spares shop, for the next 60k miles and never had any issues, go figure. The bottom line is do what ever gives you peace of mind and if that means an oil and filter change, it's worth it to you. Edit......I might add that when I bought a very low mileage, 8 year old XR650 back in 2010 that still had the original oil in it I drained and refilled it with some 10w/40 diesel engine oil (high detergency) and ran it for 100miles or so to flush out the engine without any clutch slip or other oil related issues.
Thanks. That's encouraging. I did get in touch with a Triumph dealer to seek advice. They suggested that because the oil was similar spec to the handbook (SAE and API) and was a 'top up' then there wasn't too much risk. Also as the Speed Twin wasn't a 'high revving' bike then that too would reduce the risk.
If it was only a small top up I would not have expected the oil light to come on? They are usually pretty low on oil to trigger the oil light. But if the oil light is not now coming on all should be well?
Yes change the oil and filter.....how come you only notice you oil was low during a ride.....was it ok at the start of the ride? Or when was the last time you checked it? TBH a new engine should use next to no oil.....so why is it using oil....or it it? How much did you put into the engine to make you feel it was full? Can you say how you noticed it was low....and was the bike on its side stand or center stand......Massive difference....are you familiar with the instruction's in the handbook for checking the engine oil level.
I would change the oil. It's simple and would remove any concerns about mixed oil. I would be more concerned with finding the reason it was low!
A friend was convinced that one or more of the hydraulic tappets on his daughters car was sticking and not auto adjusting. So he drained the oil and filled it up with diesel fuel and ran it, not drove it, for a while and the problem resolved itself. Amazing what you can get away with if you have the courage so a mere top up with a different oil wouldn’t phase me.
How many ml could we be talking about and what percentage of the total oil volume in the lump would this be? If it were significant I would worry more about what damage had been done to the engine because I let the oil level drop so low in the first place.
Personally I think there's a lot of hype around oil choice. Sure, I aim for the specs required by the engine manufacturer but I don't get sucked in by "advertising" on the label. Why is one oil brand twice the price of another of the same spec? When I had my FZR1000 back in the '90's, Yamaha recommended a specific brand of lubricants. I asked a Yamaha rep at the NEC bike show why and he said "because they sponsor our race team". Low oil is way more dangerous than the "wrong" grade, not only leading to potential oil starvation/pressure loss but also leads to hotter running.
