I've seen many times the lend-lease help cited for Russia, about 450,000 trucks (actually they were "jeeps and trucks" so it's hard to know trucks exactly). However, what I've never seen is citing how many trucks Russia already had, vs how many Germany had. Without these numbers, the lend-lease stuff cannot be compared to anything.
How many trucks did Russia have at the start of Barbarossa (1941 Jun 22)? How many did Germany have?
I googled around with various phrases, but it's hard to find something not talking about lend-lease. I did find the wiki page for Soviet automotive industry which has some things:
In 1937, the Soviet Union produced over 200,000 vehicles, mostly trucks, putting the country in second place worldwide by production of trucks.
But wikipedia contradicts itself here, because according to its chart...
...it was not 1937, but 1938. Maybe it was a typo?
Also note that this is for all automobiles, not just trucks. It really annoys me when it says things like "cars were only a small share of all vehicles produced in the early years of Soviet production." How small is small? What is the number? How do they know it's small unless they had the actual numbers to look at and judge it small? Why would anyone then omit the numbers?
Another thing I could not find was the weight of these trucks. I seem to remember the lend-lease trucks were 2.5 tons each, but I went looking for a source and couldn't find it. How many tons were the American and Soviet and German trucks?
As for the Wermacht, all I can remember off the top of my head is that 80% of the army was horse-drawn. But that is just a relative percent and I have no way of translating it into an absolute number of trucks.
The Wermacht stuff seems to have more info, or maybe just chat, on the web. I found this website which has entries 32,558 , 53,348 , and 51,085 for 1939 to 1941 for "military trucks and lorries". So if you take half the 1941 number, it would appear that Germany had about 112,000 trucks by Barbarossa. However, this is just production for those years. It does not say how many already existed beforehand. It does not say how many were lost between 1939 and 1941. And also, I could not find any source citation on that website.
I also tried to tackle this question from another angle: How many trucks did the USSR lose in Barbarossa? That could give us an idea of how many they had. But no luck there either.