[Rahul Bhalgat]

Originally Posted by Mortis

Would this be applicable to the newer models as well ? Mine is from 2018. Im assuming it's the same old gearbox that Maruti has been using in their cars for years. Don't really see many detailed discussions on manual gearbox models.

The manual gearboxes haven't changed in their technology. Moreover, the manual gearboxes do not circulate the oil through small passages inside the parts (like engine oil flows through the small holes in the connecting rod). It is a splash lubrication for the bearings, the gears and the sliding surfaces. So you can go ahead with 75W90. 75W80 also shall be fine.

[hserus]

Originally Posted by Rahul Bhalgat

It is 75W90. I am attaching the screenshot of the owner's manual of my SX4.

You can use 75Wanything for a mono weight 75W oil specification. Antique gearbox, it won't matter what you use as long as you change it regularly on schedule.

[vrprabhu]

Originally Posted by vrprabhu

.... use 75w90 (Chemoleum brand) gear oil for Hyundai Eon? 75w85 seems to be unavailable locally.... most of the oil dealers are suggesting 80w90....

Originally Posted by sagarpadaki

Yes, you can use 75W90 instead of 75W85. The gearshifts may not be as smooth as before when the gearbox is warmed up because of the heavier 90 grade but cold shifts will not see any difference

More than a month after the gear oil change (75w90), the car is running as usual (just city runabouts within 10 kms radius). If anything, the shifts are slightly smoother - but the reverse is slightly hard (since there is no synchro for reverse?)

[Rahul Bhalgat]

Originally Posted by vrprabhu

If anything, the shifts are slightly smoother - but the reverse is slightly hard (since there is no synchro for reverse?)

True, the reverse does not have synchromesh.

For the forward gears, the shifting experience shall improve further whenever you change the worn synchro rings, especially for the 1st and the 2nd.