Before I top the 4.2 up with oil...

[robsco]

... I've spoken to Forza West who last serviced the car, who tell me they used Mobil 1 0W-40. I ordered 5 litres of Millers XFS 5W-50 the other night for top-ups. I presume topping up with this while the car is running a different viscosity isn't recommended, or does it not make any difference? The car has gone from full on the dipstick to about 3/4 full in the last 300 miles, so I'd prefer to top it back up to full ASAP.

Thanks all.

[scotty_d]

I would just stick with whats in it just now Better safe than sorry to save a couple of quid just go buy a couple of L of whats in it till next oil change.

[FUBAR]

Isn't 0w-40 a little thin? Mr OpieOilyBlokey's advice thread.

[C3BER]

The trick with oil is rather simple.... NOT! There are so many variables from quality of engine to temperature, age and speed and every other combination in between. As a guide line: perfect = thin oil, worn = thicker oil. As for your engine what are the hot and cold oil pressures. If low and it's not an oil pressure spring issue go for a thicker oil and if pressures are normal stay with the oil your indie uses.

[robsco]

Oil pressure is great, 70psi cold and never drops below 60psi. Looks like if the oil is a little thin, I should probably bite the bullet, order another 5 litres of 5W-50 and change the oil.

[C3BER]

When I'm really going for it and using the gears etc and with the oil really hot I drop to 40psi.

[robsco]

C3BER said:

When I'm really going for it and using the gears etc and with the oil really hot I drop to 40psi.

Currently I daren't look anywhere but at the road ahead when I'm going for it. Frighteningly quick.

[C3BER]

Yes they are a seriously quick 130mph squirt car ;-) . Now you see me now you don't fun. Get yourself onto a runway to see how truly fast they are and to see how big your balls are. 170 plus is so much fun but the heavy shooters on here hitting 190 plus have Fubars space hoppers :-)

[C3BER]

Yes they are a seriously quick 130mph squirt car ;-) . Now you see me now you don't fun. Get yourself onto a runway to see how truly fast they are and to see how big your balls are. 170 plus is so much fun but the heavy shooters on here hitting 190 plus have Fubars space hoppers :-)

[ukkid35]

Don't forget these are 'old fashioned' Flat Tappet engines, so it's not just viscosity you need to consider.

[FUBAR]

C3BER said:

Fubars space hoppers :-)

[verminator]

Why would'nt you use what it recomends in the hand book?

[gruffalo]

verminator said:

Why would'nt you use what it recomends in the hand book?

Technolgy moves on in oils as well as every thing else, I just want to use the best, she deserves it:-)

[ukkid35]

Have a look at the tappets in my engine in the 'Impossible' thread if you want to see what happens when an oil with insufficient ZDDP is used. To be honest I'm surprised the cams aren't wrecked as well, which suggests that they might be new.

New oils that are SM/SN rated are not appropriate for use in 'old fashioned' Flat Tappet engines. New isn't always best.

[robsco]

ukkid35 said:

Have a look at the tappets in my engine in the 'Impossible' thread if you want to see what happens when an oil with insufficient ZDDP is used. To be honest I'm surprised the cams aren't wrecked as well, which suggests that they might be new.

New oils that are SM/SN rated are not appropriate for use in 'old fashioned' Flat Tappet engines. New isn't always best.

What oil are you recommending?

[ukkid35]

robsco said:

What oil are you recommending?

I'm not recommending any particular oil, as this depends very much on how and when you use the car. But I am saying that you need to make sure that whatever oil you chose it has sufficient ZDDP. SM/SN are restricted to a maximum of 800ppm (to protect modern cats), but it is widely accepted that 1200ppm is the minimum for flat tappet engines, and 1400ppm is the minimum for engines with aggressive cam profiles.

I don't follow my own advice to the letter, as I use Penrite HPR15 which is only 1150ppm, in my other car. I haven't put oil in my AJP yet.

[robsco]

ukkid35 said:

I'm not recommending any particular oil, as this depends very much on how and when you use the car. But I am saying that you need to make sure that whatever oil you chose it has sufficient ZDDP. SM/SN are restricted to a maximum of 800ppm (to protect modern cats), but it is widely accepted that 1200ppm is the minimum for flat tappet engines, and 1400ppm is the minimum for engines with aggressive cam profiles.

I don't follow my own advice to the letter, as I use Penrite HPR15 which is only 1150ppm, in my other car. I haven't put oil in my AJP yet.

Thanks. Though I can't say I understand what you've posted.

I bought a couple of litres of Mobil 1 0W-40 (what the car is currently using, and the recommended oil in the TVR handbook) to keep her topped up while I determine what will be best for the car. If the Miller's isn't sufficient, I'll just leave it in the garage. I found a technical PDF for it on Opie's website but there's no mention of ZDDP or suchlike.

[ukkid35]

robsco said:

I bought a couple of litres of Mobil 1 0W-40 (what the car is currently using, and the recommended oil in the TVR handbook)

This is what it says in my copy of the owners handbook

[robsco]

ukkid35 said:

This is what it says in my copy of the owners handbook

Odd, my handbook says Mobil 1 0W-40. Perhaps the 4.2s and 4.5s have different oil recommendations, though you wouldn't expect that to be the case.

[cerb4.5lee]

I have used 0w-40 mobil 1 in mine for the last 5 years & have been challenged a few times that it is too thin,but i thought this is what it recommended in the handbook.