The Lotus Grand Tourers

Opie oils tell me that Lotus now recommend 10W/60 for the Excel. Has anyone here used this spec? If so, what improvements or benefits have you found?
Here, where summer temperatures can get into the 40's, it could, perhaps, be beneficial?

I used it, and have no real understanding of how oils are built up and how they react to local conditions, but, i put it in my engine and thought it very thin for an engine of age, you could here the change in engine noisefrom standard oils on start up and i didnt like it. I talked to Mike Taylor and he uses Valvoline 20-50, in both his road engines and race engines, so that is what i use, i change it every year or so (dependant on how many miles and my driving) and she sounds as sweet as a nut.

I've used 20w/50 for quite a while now, but used 10w60 previously. When cold the 10w/60 will be noisier than the 20w/50, but when hot it will be thicker than the 20w/50, that said, I still don't plan to go back to it. The stuff I use now is also Valvoline.
I asked a mate to pick up 4 cans of it when he was at Mike's a couple of weeks ago, not quite as cheap as I could get it, but I work on the basis, Mike (and others who do the same sort of thing) have to make a profit, or else their businesses wouldn't continue to exist, so when i want a part (second hand or new), I'm glad Mike is around to supply that, or else I'd spend a fortune on a new part from Lotus, so the extra few £s on some bits are more than recouped on other items.

BTW, the numbering system tells you how the oil will be when hot and cold (w for winter).
20w/50 is as thick / viscous at cold temperatures as straight 20 oil would be at that temperature.
20w/50 is as thick / viscous at hot temperatures as straight 50 oil would be at that temperature.

Andy

I'll go along with Andy..............Oh and i get my valvoline from Mike aswell

Yep the 10/60 castrol is thicker, not thinner, at high temperatures which is especially useful when pressing-on. The downside is that when cold the engine is a tad noisier...but that doesn't harm the engine...but you might think does though. I've used nothing else for last 5-6 years.

Oil pressure when stinking hot is significantly higher than the 10/50 Mobil 1 I used previously.

The other real benefit is significantly reduced oil consumption (thicker oil when hot and less is lost via rings and inlet valve guides) , which in the long run makes the Castrol 10/60 less expensive than it may appear.

If you live in a warm climate then it's a no-brainer....10/60 is the one to use ...it will also be less noisy on start-up than in a colder climate like Britain.

Agreed ^^^ When up to temp the 10w-60 is thicker then the 20w-50 and this is measured at 100degc. The 10w is thinner on start up then 20w so flows better from cold, and as already said the fact it is a little louder on start up is not a problem.

I am unsure why Lotus have started recommending 10w-60 for these, I would have thought that 10w-50 and 15w-50 are also ideal, my only gripe with 20w-50 is its poor cold flow.

Cheers

Guy

oilman wrote: I am unsure why Lotus have started recommending 10w-60 for these.
Guy

I think reduced oil consumption may swing it due to the relatively wide engineering tolerances of the Lotus 900 series engine which leads to significant oil consumption on Mobil 1 etc even in a low mileage engine. This is the main reason Kelvedon Motors (official Lotus repairer) recommended 10/60 instead of the official Valvoline or Mobil 1 for my low mileage engine about 6 years ago.

Makes sense, SAE60 is a good coverup for these issues. BMW and Alfa also recommend it in certain applications for the same reason.

Cheers

Guy

Kelvedon Motors (official Lotus repairer)

My engine was built by Mike at Lotusbits and as i don't get to use "official Lotus" people up here then i am happy to stick with what he reccomends and as has been mentioned in one of the post earlier we need to support the smaller lotus people as to be honest they are our life savers in respect of bits and bobs, i find no issues with this oil, i change it regularly it is very cheap and it has recomended properties. i think that in the end it is personal choice and mine is to stick with Mikes advice.