Gary Paffett had the honor of giving McLaren's new MP4-25 its first laps at Valencia on Monday, dialing in the car ahead of the arrival of Lewis Hamilton and Jenson Button.

McLaren has high hopes that the car will help the team return to title-challenging form after the troubles it endured at the start of 2009. Although it was hard for any team to make a firm judgment on the pace of their cars after the opening day of testing, Paffett was upbeat about the early indications from the new McLaren in an interview with AUTOSPORT.

Gary PaffettQ. What's the impression from today?

Gary Paffett: The car feels good. We started off slowly, just doing an install to make sure everything is OK. To be honest, no problems at all. We've run the car all day and we haven't had any issues with any technical problems on the car so that's the first thing out of the way.

The balance and everything, it feels quite good. The car is pretty stable, especially in the high-speed. There are obviously some differences with the narrower front tires that everybody has got to try and get over but, with the simulation work we've done over the winter, we've got a car now that is quite similar to what we expected it to be.

We've got to be relatively happy with the day, we got through it without any problems. The initial feel of the car is good but you never really know the speed. Especially with the regulations this year with the fuel, you don't know what people could be running. In the past it could be 10 to 70kg, now it's 10 to 150kg, so it's very difficult to know where people are and what they are running. Generally, we're happy with today.

Q. How much of a difference have the new tires made? Can you isolate the wheelbase increase and the tires?

GP: The biggest difference is, for sure, the tires. With such narrow front tires, and the shape of them as well, they are a lot more curved than the others so you do lose a lot of front grip, and that's what we've got to try and get back. That is the biggest difference, certainly, out of all the changes we've had this year.

Q. Do the tires behave differently under different loads or is it just slightly less grip?

GP: It's generally less grip really, so obviously braking, you have less front end braking, and in the corners. Because the aero takes over more at high speed, the high speed is not so much of an issue – but certainly the low- and medium-speed corners, where you really demand mechanical grip, is the biggest issue and the biggest thing you've got to try and overcome.

Q. Can you feel the wheelbase difference?

GP: You can. We've done work over the winter trying to simulate that and you already get a feeling of the car. We haven't driven the MP4-24 for a long time, so you are kind of used to that now. We've made some wheelbase changes in the past and this is a fairly big change. You can feel the difference but the biggest difference is certainly the fuel weights that you are running, and the tires.

Q. You tested last year's car before last season when it was still in trouble and still very difficult. Can you compare the feelings of confidence in relation to where you were 12 months ago as a baseline now?

GP: It's very difficult to say because even from the first thing last year the car felt, not too bad, but it wasn't great. I mean this car feels a lot more stable and feels like it's in a better position, but we still don't know if it is fast enough and we won't know until we get to Bahrain. I don't think anyone's really come and blown everyone else away yet, like Brawn did last year, so we are just waiting to get on and do some more days. It's only day one gone, we'll do some more days testing and start to get the other race drivers' opinions on the car and start developing it.

Q. Was the spread of times today pretty much what you'd expect?

GP: It's difficult because we did some normal running in the morning. We were fairly close, and then in the afternoon we concentrated on higher fuel, longer runs. Some people did other stuff, so it's so difficult to know where people are. The Ferrari looks quick, the Sauber looks quick and the two guys in the Mercedes look pretty quick as well so I think, personally, it's sort of what you'd expect really, but again it's just impossible to know at the moment.

Q. We saw Schumacher and Massa were clearly pushing at the end to do their thing, and Schumacher was obviously eager to get decent laps in today...

GP: There are people out there who are very keen already to prove themselves, and prove that they are back. Michael has got a lot of pressure on him, obviously. For myself, it's just a case of doing the job of trying to develop the car. We just get miles on the car – miles are more important than anything else. To put mileage on all the parts and see if you have got any failures, and that's what we did today – we just kept going around trying to get miles on the car.

Q. Did you get a chance to tinker with any setups?

GP: Yeah, we played with some setups during the day while we were doing the changes and the long runs, and the car reacts in the right way, the way we expect it to. So it's performing pretty well in that respect. Overall, very happy with the day.

Q. So no [aero pattern tracking] green paint tomorrow?

GP: You never know.