Except with online races, you aren't always guaranteed a 1st place finish, or a race for that matter since it takes forever (I've waited 5 minutes sometimes) to connect. With the Daytona Oval course (which I used), I knew exactly how long it took me and I never got less than 1st.
I am not so good for winning every online race yet

. I started having differences +15-20sec from the online records (for specific car,not general) and I have dropped it to 4-8sec and still improving. I re-started the game recently and I am not going straight to the online before knowing how to drive propertly. I don't want to be one of the jackasses with no skills that play online and destroying the races...
You don't need to win in order to amass quite a fortune.....they made the credit pay outs online rather large for this specific reason - so people could buy F2007s easily (so they could make an online event for people to use them in).
4-8 seconds off the pace isn't bad but really you shouldn't worry about it too much, playing online isn't just about speed, you need experience in reacting to race situations, not just hotlapping. So its best to get out there racing rather than sticking to time trials worrying about whether you're "good enough" or not yet. I'm sure you will find people of a similar ability to you especially on this forum, so just meet up with them and race.
Trust me, being slow isn't what people are referring to when they are referring to the idiots online - we're referring to the dirty drivers, new drivers who are still learning the ropes are obviously always welcome!
Even if you can't finish in a great position all the time, you will earn way more money than offline, allowing you to buy more cars quicker and open up the enjoyment of this game a lot more. Plus, playing online is one of the great elements of this game.
If you want to pace yourself online by racing people of a similar skill, I suggest you check some of the threads around here (stuff like "Enhance your skills" etc) and get racing! You have to start some where and some time, and the more experience you have (good or bad) the better, speed comes with experience, not just practice.