Basic Q's: when to oil check; which oil to use; is 95 octane really bad?

1. Depending on when I check the dipstick I get a good or bad reading...

- Checking before going anywhere (engine cold) the oil is near to low.

- Checking after driving somewhere (even 1 hour later) the oil is up to or over full.

I've got the US Supra guide but it doesn't indicate WHEN exactly to check the oil (it just says with the engine off!). So what's the score?

2. I know there are plenty of opinions on which oil to choose (bear in mind I have a stock Supra) so would 10W30 be bad or not? My mates swear by Mobil1 5W50 (I think) but that seems pricey/not available in great quantities around here.

3. I've got the JPNZ Japanese translated Supra handbook which strangely says that the car can use 95 octane fuel and even fuel as low as 91 octane. Is this feasible? Due to general lack of Super Unleaded I have been forced onto regular 95 unleaded several times now but 91 octane?!

I heard that RX7s have an ECU that switches into a lower setting if the fuel isn't as good. Does the Supra do anything similar if 95 octane is used (so it feels worse but still works)?

Cheers for any enlightenment,

P.S. I know question 2 has been asked many, many times but no-one seems to use 10W30 despite the US Supra guide showing it to be useful for the range of UK average temperatures.

Ice

Im not going to comment about the Oil, but I'd put as high octane as possible in your Supra if you wanna maintain it.

Basically, 100 octane is what they run in Japan, so try and stick as close to that as you can.

You're also sacrificing performance putting cheap shit petrol in.

It will run on 95, but you need to reset the ECU so it will learn the new fuel. If you don't reset it will learn by it's self. but may give poor performace for many miles. If you raise the octane you should do the same. On a stock car 95 won't hurt.

I always check my oil cold, always have.

Oil should be checked COLD on a LEVEL surface.

It should never be allowed to go below LOW and should be between LOW and HIGH. Also never overfill it above HIGH.

5.0lt capacity if I remember.

When you run the engine the oil gets distributed around the internal engine components and thus hardly any sits in the sump, but loads gets sprayed up the dipstick. You need to allow all the oil to drain back down to the sump and then check it.

So by what you say I think you need some oil.

I use Valveoline SynPower, cannot remember the spec but, it's never given me any problems on a modded car for the last 3.0 years. Mobil1 is too thin in my experience and gets burnt up really quickly by the turbo bearings.

You need to change your oil at least every 5K miles and when you get more and more mods and you driving style is hard you should think about 3K mile changes.

Always use Fully Synthetic oil.

It's the life blood of the car so skimp on this and expect big bills later.

As for fuel it's O.K. on a stock car to run 95RON but you won't be getting the best out of the car.

Try using SuperUnleaded as much as you can. Especially when you start modifying the car you'll definitely need the 97RON (and more if you use an octane booster)

If I put 95RON in mine now (with no choice) I have to drive like a snail as it back/misfires on high boost. Probably detonation which is not what you want.

Regards

Pete