Sebastian Vettel made an underwhelming debut with Aston Martin at the 2021 Formula 1 pre-season test. The four-time world champion accumulated 117 laps but was constantly hindered by transmission and turbo issues throughout the test.When asked how far behind he was in his preparations, Sebastian Vettel said:"One hundred laps! Obviously, I would have liked to just get more mileage. That's the main thing.""So today was very busy and I tried to make use of the track time which I felt I did and it was very good for me and I learned a lot of things, so now it's obvious to remember all these things and give feedback and remember going forward."Not what we were hoping for but Seb is still remaining positive. 🤜🤛'There's more to come, so stay with us.' 😉#SV5 #F1Testing pic.twitter.com/bid6XFSSOX— Aston Martin Cognizant F1 Team (@AstonMartinF1) March 14, 2021"As I said, overall it's probably 100 laps that I'm short, then probably something similar for Lance [Stroll]. We both obviously didn't get what we wanted. But it's not a big deal, it's what it is and we've got to move on."Sebastian Vettel stressed that greater importance was put in understanding the car rather than trying to find limits on a single fast lap."More important than one lap is to really understand the car and for that, I think just doing more and more laps help,” he said.“So then doing a push lap is just putting the things together, or the lessons that you learn or acquire, so I'm not worried about that.""So there's plenty of time and it will be a busy year, so we try to obviously start well. We had a mixed test with some hiccups."Steep learning curve ahead for Sebastian VettelAll good things come to an end...The final day of Pre-Season Testing sees the team complete 136 laps and cover 735km. 💪 #F1Testinghttps://t.co/9KsPMndyO2— Aston Martin Cognizant F1 Team (@AstonMartinF1) March 14, 2021Sebastian Vettel conceded there was still uncertainty about their position on the pecking order and that he has a steep learning curve ahead of him.Speaking about the pecking order, Sebastian Vettel said:"Where are we? I think it's very difficult to say in terms of competitiveness. We haven't done many runs that probably equal other people's runs to give us a bit of a comparison.""So, yeah, I think for us the first couple of races will be especially for me a steep learning curve, but we take it from there."The lack of mileage is not ideal for Sebastian Vettel as he joins a new team as the lead driver. The four-time champion can't afford to lose out to his young Canadian teammate Lance Stroll.