So yeah what seems like an eon ago i had had the stock oil interwarmer removed and was quite happy about it and then someone hooked up an oil temperature gauge to their GT and measured the results of their oil cooler delete. Yeah, eye opening but there was some concern over the quality of their gauge so we needed a second set of results. I got a fairly basic analogue Stack Oil Temperature gauge and got it hooked up, I should have posted this stuff Dec 2022 then July 2023 but i never so here we go.
Dec 2022 - about 3degC outside air temperature and it's fresh but dry, Exec summary - 90-92degC oil temperature (basically just far enough past the 90degC marker to see the marker, gauge back face then needle) in all steady state driving. Actual driving speed did not seem to make a difference to the oil temperature with the only difference being how fast the oil gets to said temperature and it can take a surprising distance to get up to that temperature. So, 50mph, 70mph for 30 miles give or take the occasional lift and coast for traffic it is the same temperature for the oil at 90-92degC so it's very steady Was also in stop start traffic for 25 minutes and oil temperature stayed the same 90-92degC. CHT on the dash would vary from 95-100degC throughout all the above
Come March ish 2023 the ambient temperature was a bit nicer at 12degC and oil temperature under same conditions as above was 100degC, outside air hotter makes the engine oil work a bit more which is fair enough.
June/July 2023 and boy was it hot here, 23-30degC some days. Brilliant stuff. Well sadly never got the chance to hoof it last summer but 23-30degC ambient temperatures outside and in fairly enthusiastic driving without pushing the revs to the red, the oil temperature never got above 103ishdegC temperature, could see the dial face between the 100 and the needle position. The only time it rose above this was climbing the Applecross (Bealach na Ba) road. Climbing to 2050odd feet above sea level, 25degC weather, air con on (obv!), 20percent gradients, high loads on the engine pulling out of alpine style hairpins (three of them) and constant stop / start / on the power between passing places and blind corners on a single track road. Oil temperature hit 110degC which actually matched the CHT readout as well. TBH most of the time they are pretty close to each other with steady state driving, when hoofing it the oil temperature can be higher than CHT but usually not by much.
So in conclusion, i think for the road in this climate, I'm fine without the cooler. Hoo raa