Really? But what about Fall Blau? The Luftwaffe? Lack of fuel seems to have affected the war a lot - at the very least I imagine more oil would make Germany more dangerous...
See my edit. Add to this case. Russian geography, weather, American LOGISTICS training and help, and Allied manufacturing cycles. Machines wear out, training is perishable, and the enemy is there. If he can outdie you, he wins (WW I; western front, Germans run out of soldiers by 1918.). Guess what is not in the 1943-44-45 German draft cohorts for Russia? Sons of WW I KIAs as casualty replacements for current WW II KIAs. Their fathers were killed in France 1916-1918. And... if he, the enemy, gets smarter and fights better than you, (*Red Army 1944), your goose is definitely cooked if you are German. Add this... The Russians are motivated by two most basic and strong human imperatives... survival and REVENGE.
EDIT: Slave labor is not as efficient as motivated factory workers, and what good does oil do one if the products produced are junk in battle? Take a look at the ACTUAL exchange ratios in one category, Allied vs. German tanks in the year 1944. From American records the US Army lost about ~1,300 Shermans ir-repairable due to battle damage in France. In theater (France) in the same campaign, the Germans lost roughly the same number of Panthers to US action. Tank vs tank. Not too good. I think the exchange ratios against the T-34 were a bit more lopsided, something like 1.3 T-34s for every Panther, but the Russians were more tank aggressive and dependent in their combined arms drill. The point is, what good was oil to a defender who did not have to move much in comparison to his attacker? Not much. Germans in the attack were not all that efficient past 1943 either. They had the oil stocks for Kursk and initially for the Bulge. Results? The defenders used hasty defense obstacles, terrain, and better combined arms to snuff the two offensives before they could really get started and went on to bulldozerkrieg their ways forward.
Not buying into oil as a magic cure all. One has to know what one is doing. Did you know that the IJN had the best organized oil supply system in the world for its fleet in 1942? They had enough oil to mount operations and they mounted them. BUT, they were incompetent strategists and inept in the operational art. Their opponents only had to last through the initial rush and the ceaseless pressure of numbers, time, distance, manufacturing cycle and kill-off of trained personnel would leave the IJN vulnerable and helpless to a stronger enemy, who by late 1943 was much better at warfare than the IJN was. Oil was the American handicap in the first two years of the Pacific war. TANKER SHORTAGE. And yet... Does it kind of sound familiar?
15% of American power ~ Japan's total war effort. 1=1 from 1942 until 1944.
Oil as a factor? By March 1943, yes for the IJN on offense, but the Americans were sucking on empty, too. You don't see Task Force 58 until late 43, and then not at full power until mid 1944 when America has enough fleet trains built to sustain it. Of course by then, the Japanese were dead empire walking. Much like the Germans for the same reason. They were on the wrong end of the applied force equations. When the crunches came in June 1944 at approximately the same times for the militarists in Berlin and Tokyo, it was not oil that was the doomer. They had simply run out of trained men and materials to mount a successful defense. Defense does not have to move much, but it has to be effective. It was not for the Germans or the Japanese. System of systems it is called, and oil is a "small" part of it.