Matt Bloomfield is still looking for his first win as Oxford manager after a second successive 0-0 draw.
QPR held the relegation-threatened Us goalless in a game of few chances played in difficult conditions, and for Rangers too it was a second stalemate in succession after their battling draw at Stoke last weekend.
The result does not help Oxford's cause, although they did close the gap on Portsmouth and Blackburn above them to four points.
Bloomfield made just one change from the team that started Saturday's 0-0 draw against Bristol City, with young Turkish midfielder Yunus Konak dropping to the bench.
Also among the Oxford substitutes was Jamie McDonnell, who had just signed on loan from Nottingham Forest.
Rangers enjoyed the bulk of the possession in the opening minutes but it was the home side who had the first effort on goal, right back Sam Long driving over from 25 yards.
At the other end, Paul Smyth sent a dangerous low cross flashing across the front of Jamie Cumming's goalmouth after being picked out by a 50-yard diagonal pass from Karamoko Dembele.
The strong, swirling wind made conditions difficult and it took three minutes for QPR to take a corner because the ball would not stay still near the flag.
Oxford had wingers Stan Mills and Myles Peart-Harris hugging the touchlines when they had the ball and on one occasion when he drifted infield, Mills let fly from distance and the effort did not miss by much.
Smyth went even closer for the Hoops on 33 minutes with a shot from the left of Oxford's box that Cumming did well to turn for a corner.
Oxford were forced to make a change for the second half with Brodie Spencer replacing the injured Michal Helik, and Long switching across to centre-back.
There was a lengthy delay in the second half for treatment to QPR left-back Esquerdinha, who was stretchered off the field following a hefty challenge.
Long brought a good save from Rangers keeper Joe Walsh, turning his shot for a corner, as United pressed again.
Mills held his head in his hands after turning a fine cross from Peart-Harris over the bar from four yards at the far post - a miss that summed up the match.
Oxford's Matt Bloomfield:
"I think there's been real positives in terms of the buy-in from the players, the energy and the effort, and the defensive structure has been very good both games, limiting the opposition to very little.
"And we've created some big moments. Unfortunately for us, we've not been able to take them. We've created enough to win both games.
"We want to create more clear-cut opportunities, that has to be said, but at the same time the boys are committing everything, the crowd were great again tonight.
"There are things we need to work on, but we knew where we were coming into the building.
"We wanted to win both games and we've created enough to do so, but we've been unable to take them.
"I thought Jamie McDonnell was very good when he came on. He's a quiet, unassuming lad but on the pitch he's a real warrior, he wants to win in everything he does.
"Sam Long was excellent when he moved across to centre-half as well.
"We know we've got some tough games coming up but both Bristol City and QPR were top-half teams.
"Of course we wanted to get off to a good start and win as soon as we possibly can and it's not happened, but we believe in the work we're doing."
QPR's Julien Stephan:
"It was a game in very difficult conditions, a lot of wind and rain. I think in the first half we did quite well, we had more control, and they shot only two or three times from outside the penalty area.
"We had some good moves on our left side. The lack of quality after that to be able to create big danger was disappointing. It was more difficult for us at the beginning of the second half but they had only one situation and it was a good save from Joe Walsh.
"(Other than) that we didn't concede a lot and at the end and in stoppage time we had two good opportunities.
"For us it's a second clean sheet in three days away from home, and the third clean sheet in four games so in terms of consistency we are good, and we see the positives of taking a point here."
