Motus Gear 300 transaxle oil

[JonnyCJ]

Going to be changing my transaxle oil fairly soon and using Motul Gear 300 rather than Castrol BOT 270A.

I have a manual and from all the research I’ve done, the Motul is the closest spec to the Castrol. I believe the SS needs the Castrol though.

Question is, do I go for standard Motul 300 or Motul 300 LS for LSD cars ?

[BigMig]

I believe it’s just the regular 300, have a look at Redpants lol site
https://newstore.redpants.lol/product/motul-gear-3...
It’s what I put in mine when I changed it out last year. I would say the 1st to 2nd shift when cold is slightly worse than with the Castrol, but when everything is warmed up all is good with no discernible difference in shift quality.

[JonnyCJ]

That’s where I’m a little unsure James. Opie Oils come up with the LS version when I pop my reg in and afaik we have LSDs in the V8V.

[V8V Pete]

All Gaydon Vantages have a mechanical LSD.

Why would you not want to use the oil that was specifically designed for your car (other than price)? You wouldn't put cheap tyres on your Vantage, would you? Or is somebody suggesting the Motul oil is actually better than the recommended Castrol?

[klee168168]

Do you know how often you have to change the transaxle fluid?

[JonnyCJ]

V8V Pete said:

All Gaydon Vantages have a mechanical LSD.

Why would you not want to use the oil that was specifically designed for your car (other than price)? You wouldn't put cheap tyres on your Vantage, would you? Or is somebody suggesting the Motul oil is actually better than the recommended Castrol?

Having looked at the specs vs price for Castrol and Motul I'm very happy that the Motul will provide equivalent protection for my manual box. I don't drive it in the winter (March - October) and don't do a lot of miles.

We all know the Aston tax on various items and in this case, I think it's a sensible alternative.

I also don't put the oil that was originally spec'd for the engine in either - things improve over time.

[BigMig]

I believe in a pragmatic approach to alternative components and consumables, often with the view of finding a more cost effective solution, but sometimes to provide an enhancement or benefit to the OEM parts.

Just because the Motul is available at a lower price point, it doesn't necessarily mean it's an inferior product. Picking up on Jonny's point, technology does move on but a vehicle manufacturer will not re-evaluate products over time, even for current models let alone ones no longer in production. Which is why the AM recommended tyre for the V8 remains the good old Bridgestone RE 050, which is at least 15 years out of date compared to current offerings from Michelin, Pirelli etc.

Also, I do a lot of work on my car myself, and have many frustrations to share about the penny pinching that's gone on at both AML in designing and assembling the cars, and within the dealer network for either missing service items or bodging repairs to failed components.

[BigMig]

JonnyCJ said:

That’s where I’m a little unsure James. Opie Oils come up with the LS version when I pop my reg in and afaik we have LSDs in the V8V.

Hi Jonny, just done a bit more reading and the Castrol BOT270A is not an LSD specific oil as it's an API GL4. The API GL5 oils for LSDs, may or may not be unsuitable for use in transmissions due to the way they can react with yellow metals in for e.g. synchro rings.

So although we have an LSD, beacuse its also a transaxle then GL5 oils may not be the most appropriate choice.
Having said that the Motul Gear 300LS does state that it's compatible with all seals and transmission components.
https://cdn.opieoils.co.uk/pdfs/motul/Motul-Gear-3...

So, no conclusive answer as there could well be other additives in the Castrol oil that makes it more suited to the transaxle than the standard Motul 300.

[JonnyCJ]

klee168168 said:

Do you know how often you have to change the transaxle fluid?

Every 4 yrs or 60,000 miles.

[SL500UK]

Did they not change this to every 60,000 miles (or more) and not at every 4th service? I'm fairly sure that's what an AM service centre told me.

[Craig elam1]

I used castrol syntrax limited slip 75w-140 from euro car parts when i did mine a couple of services ago ( about 5,000 miles)
Used to get awful lsd shudder when cold , no longer the pack shows approv from bmw, zf, and approved for use in nissan GTR!!, another option perhaps

[Craig elam1]

Sorry speedread this and got wrong end of stick, db9 auto diff is completely seperate to box, so does the vantage diff and box share lubricant?

[JonnyCJ]

Yep - it’s a transaxle, so all one unit effectively.

[Cornwall1]

JonnyCJ said:

Going to be changing my transaxle oil fairly soon and using Motul Gear 300 rather than Castrol BOT 270A.

I have a manual and from all the research I’ve done, the Motul is the closest spec to the Castrol. I believe the SS needs the Castrol though.

Question is, do I go for standard Motul 300 or Motul 300 LS for LSD cars ?

When I bought my 2006 Vantage in 2019 I asked the forum which oil I should use.
Mike from Banford Rose replied and said he would only use Castrol BOT270A.
I don't know why you would not use it.

[AdamV12V]

Googled both the castrol and the Motul and there seems to be just £4 difference in the price.

So unless the Motul is better I am not sure why you'd want to save less than the cost of a gallon of petrol or a pint of beer on what seems to be a fairly important maintenance job?

[JonnyCJ]

AdamV12V said:

Googled both the castrol and the Motul and there seems to be just £4 difference in the price.

So unless the Motul is better I am not sure why you'd want to save less than the cost of a gallon of petrol or a pint of beer on what seems to be a fairly important maintenance job?

Can't find 5l Castrol for less than £189, 5l of Motul is £99. Be interested to see where you get the £4/l differential. I would totally go with the Castrol for a SS transmission, a manual that doesn't go out in the cold Motul is equally up to the job.

£100 here and there on various things soon adds up. If you look at the alternative parts thread you'll see a whole host of areas where savings can be made, without compromising mechanical integrity, performance etc etc.

It keeps the cars on the road and ensures that we can continue to enjoy them without feeling that the maintenance cost is prohibitive.

[V8V Pete]

JonnyCJ said:

I would totally go with the Castrol for a SS transmission, a manual that doesn't go out in the cold Motul is equally up to the job.

I'm interested why you differentiate between manual and SS Jonny. The actual gearbox is basically the same. The only difference with SS, as far as I know, is that the selector is operated hydraulically rather than by cables from the manual gear knob. I'm pretty sure the internals are identical.

Anyway, I'm not criticising your oil choice, just curious and I'm in total awe of the work you've done on your Vantage, especially the subframe refurb. If only I had a garage, a lift, more knowledge/skill and some free time I didn't fill up with cycling etc etc etc

[JonnyCJ]

Wish I had a lift as well !

The SS transmission is computer controlled, so when the box is cold, it’s trying to force gear engagement and doesn’t have the feel of a person’s palm.

BOT 270a is slightly less viscous at cold (70 vs 75 viscouses) and as such, it had an easier time selecting gears when cold.

I’ve probably not explained that very well, but Redpants videos are worth a watch for a better explanation and discussion of the Motul vs Castrol.

[telum01]

The main take-aways that I have:
The Castrol was introduced to alleviate the stiff shifting issues when the gearbox is cold.
Getting the smoother flow of the Castrol when cold meant a reduction in protection when hot.
Race teams that I talk to don't use the Castrol in their cars because it doesn't have as much protection.
So my broad advice:
If you want OEM-only, or the smoothest shifting: get the Castrol.
If you want the most protection, or to save money*: get the Motul.

• Price varies, see quoted comment reply below.

I've been using Motul in my car for several years in my grey V8V and had the Castrol in my red V8V beside it...
- Yes, the Castrol shifts smoother when cold, but the Motul still shifts smoother than the original fluid used by AM before the Castrol was introduced.
- My daily liquor store runs are in sub-0C temperatures and I don't have to fight the Motul in my transmission.
- If I didn't drive my car hard, I'd get the Castrol. Given the way I drive my car, I get the Motul. I don't factor price into my decision, so take that as you will. My personal opinion is that it's a 4-year service so the price difference is spread across enough miles and time that it should be based entirely on matching the person's needs rather than price.

AdamV12V said:

Googled both the castrol and the Motul and there seems to be just £4 difference in the price.

Depends on where you're at. I've seen AM dealerships in the US charge almost 4x as much for the Castrol as what the Motul costs... $23 vs $85 per liter.