Engine Oil grades

That time of year again to change my fluids.
Just checking wki here and halfauds and opie oils and my own paperwork and they all say to use 5w/30 engine oil.
Noticed in my garage part can of 10/40 which I used last year after taking notice of the Euro Parts web site .
Not had any issues this past year so hoping using the 10/40 has not had any affect long term??

I use 10/40 with no issues

I always use 10w/40 in three cars and a van.
This may help explain.



Mazda MX5, Toyota Corolla, Nissan Primaster, Suzuki Jimny.

The grade of oil you should use isn't set in stone. It varies depending on ambient temperature, and there are several different grades that are all equally suitable for our climate in the UK. Mine is currently running a blend of 15w40 mineral, 10w40 semi synth and 5w30 synth because I had a few part full cans that needed emptying.

Jimx5 wrote: I always use 10w/40 in three cars and a van.
This may help explain....

Jim that's a really good explanation to those that didn't know.. I always used to remember it as if reading from left to right - "you get in the car and start the cold engine which then becomes hot" - but remembering W for 'winter' is just as simple if not even more intuitive.

I've always favoured fully synthetic oil as its slippery stuff and tends to stay in grade well - but is there any reason you should NOT use fully synthetic in the Jimny engine?

Max Headroom wrote: I've always favoured fully synthetic oil as its slippery stuff and tends to stay in grade well - but is there any reason you should NOT use fully synthetic in the Jimny engine?

Price is the only reason. It is over-spec, but that certainly won't cause any problems. Equally there are no advantages to using it either. I've never heard of anyone having any issues with the oily bits of the engine.

Thanks Busta.
The reason I started using synthetic was because my cousin rallied several cars and managed to continue for an amazing distance with a split sump. He said he'd noticed the drop in oil pressure but believed it was a broken gauge. Only when he saw the oil temp go off the scale some time later did he realise the situation, and stopped. There was damage to the engine but it was in his words, it was minimal, and I was very impressed by this.

I've heard that older cars (classics particularly) can tend to leak synthetic oil - as it's thinner presumably.. I did use it in my '79 Midget back in the late 80s without any noticeable leaks at all, but I now prefer to use the classic oils in that car.

Whilst on subject of oil, what are people putting in the g/box and transfer box ? and where from ? any deals out there that people have noticed ?
TIA

Joe, I'm pretty certain there was a thread here that covered gearbox oil only the other day, only I cant see it now - I think it was mentioned there about not putting additives or synthetic oils in G'boxes and axles due to it eating 'yellow metals' such as bronze bushes.
I know that to be true as it's well known and understood in the vintage car world,

Just got some from Halfords. GL4 75/90 £10 litre for my transfer box.

Stumpjumper wrote: Just got some from Halfords. GL4 75/90 £10 litre for my transfer box.

Did you buy 2 ? considering the box holds 1.3ltres ?

Thanks,