90s shock oil measures compared with modern shock oil measures

[AdrianH78]

Hi All,

6 months into my return to model car racing (boy it is tough now) and I am still using my Losi shock oil from back in the day.

My question is, its viscosity measures are 25w 30w 40w etc. whereby modern oil is rated at 250cst, 300cst, 400 cst etc. it seems

So my question is, are they roughly equivalent i.e.

25w = 250cSt
30w = 300cSt
40w = 400cSt

And why the different measure ?!

Many thanks in advanced

Adrian

[Suzukitudor]

http://site.petitrc.com/reglages/OilChart.pdf

All on here.

[Peakey]

You can still buy the old weight oils I use the TLR packs you can get from JEmodels.
I've got no idea what the conversion is but I don't think you just add a couple of 0's on the back

[xfactor]

I use AE oils. On the bottles of AE oils it gives you the weight and the CST on the bottle so you have both

[Welshy40]

I just look at the associated bottles as they have both values on the bottles. These are whats on some ive got from online.

22.5 is 238
27.5 is 313
30 is 350
32.5 is 388
35 is 425
37.5 is 463
40 is 500
42.5 is 538
45 is 575
47.5 is 613
50 is 650
55 is 725
60 is 800

[neallewis]

Originally Posted by Welshy40

I just look at the associated bottles as they have both values on the bottles. These are whats on some ive got from online.

22.5 is 238
27.5 is 313
30 is 350
32.5 is 388
35 is 425
37.5 is 463
40 is 500
42.5 is 538
45 is 575
47.5 is 613
50 is 650
55 is 725
60 is 800

Yes this is exactly right. The AE bottles WT scale is not linear and does not directly translate to the newer ISO linear standard. They therefor offer both scales on the bottles which is nice of them.
I'm also unsure on the older Losi scales, but suggest its also not quite linear to match CST as with AE.

One thing I've noticed is that some oils (core rc) do not seem to match CST scale that others use. They are a bit thinner for the same CST rating, and much more subject to temperature variation.

Whichever brand you use its always best to stick to the same brand to ensure consistency of the ratings through the range.

[mattr]

FWIW oil Wt is a made up "standard" and has little or few controls or standardised tests, So AEs Wt is different to Losis and so on.

cSt is Centistokes, and has an official international standard and test procedure.

There shouldn't be any variation beyond tolerancing between two bottles of 250 cSt oil at room temperature.

(All sorts of things happen when you move away from room temperature and/or start using the oil as the compostion of the oil and additives used will affect how viscosity changes due to temperature/time/contamination/etc)

[Welshy40]

TBH best way forwards is to test all variants until you find one that works for you. I find associated/schumacher and losi work pretty much the same in small bore shocks, big bore i admit do notice fractional changes so stick with sworkz oil in those.

[RudeTony]

Best value oil is ArrowMax - Massive bottles and available at RudeBits And it is real good too

[AdrianH78]

Thanks for all the advice, wow!

Glad I didn't trust this alone,



As I did not realise using the old measure, shock oil viscosity varied between brands

Many thanks everyone