Here it goes.
Just to make it clear, for those who did not read it all.
Mine is 2015 Sprinter with 6-cylinder engine rated at 200 HP. Single fan, who has electric clutch and 5G transmission.
ScanGauge shows engine LOaD as % of HP engine delivers at given rpm. Not perfect for testing, but gives something to compare.
So here is cruising @65 mph, 92F, where flat freeway put 73% load on the engine. Coolant temperature 99C
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This is cruising @80 mph, 100F, what gave 67% load and 105C coolant. Evidently higher speeds gives better cooling
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This is hill climbing in 85F weather. Max engine load (99% is top of the scale) and you can see 4th gear, where CC is set at 70, yet van slowed down to about 63 mph. Coolant stays at 106C
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This is city driving in 102F, where AC and my refrigerator put 63% load at idle.
Coolant temperature drops to 97C.
View attachment 220113
CONCLUSION
about 700 miles round trip, from 1700 to about 7500ft elevations, with 102F at home, when in mountains temperatures were in 80's and 90's.
The highest coolant temperature ever recorded was 109C, what happen on switchbacks climbing.
Time the radiator fan locked the clutch >>> NEVER.
Now some replies above indicate that T1N is having less efficient cooling system, but sad truth is that no T1N owner on this forum has skills/knowledge to do such testing.
Meaning there is no base to compare, when having 20 years old vehicle overheating can, beside too small cooling system, can be also radiator stone build-up.
Like I said before, driving in CA I replaced several radiators on different vehicles just becouse of that and I know 1st hand what "green coolant" can do to radiators.
My advise when you start notice cooling issues, do radiator chemical cleaning.
Worse come to worse - buy new radiator. You should be able to upgrade to bigger and/or more rows.
Relaying on fan to cool down your overheating system is not going to be lasting solution.