Is a straight 90 unavailable in the US? Our Defender asks for an "EP90" lube and there's a few smaller manufacturers producing straight 90 'GL-5' lubes which I have run in our Defender without issue and I've also used them in the diffs of my Mothers Suzuki Jimmny. In a bid to shrink my oil stocks, I use a 75w90 lube that meets API GL-4 and GL-5 so it can be used in gearboxes, transfer boxes and diffs etc.