Hi Jamie,

If your game is lagging behind, then surely your fps rate is not very good on your laptop.
This is because of a general slowdown in graphics, and is a common occurrence for any gamer. Basically, your system just can't produce enough Frames Per Second (FPS) to make everything feel nice and smooth after 15-20 minutes.

Anytime graphics lag happens, you'll typically get a reduction in the responsiveness of your controls. Your actions take a fraction longer to be reflected in the graphics on-screen because it takes your system a bit more time to create each new frame of graphics and send it to your monitor.

You can try the below fixes to have a good FPS rate on your laptop for playing NFS.

Fix 1. Get latest drivers for your graphics card

1. Head to Device Manager in the Control Panel and click on Display adapters. You'll see the name of your graphics card.
2. Then, head to the relevant website to get the latest drivers. This will be either Intel, Nvidia or AMD. Don't go to the card manufacturer's site, such as Asus, MSI, Gigabyte or Sapphire. 
3. Be sure to choose the correct model of card, and the appropriate operating system.
4. Once downloaded, install the drivers and reboot your PC if necessary. Depending on the game, you might get up to 30 percent better performance with just a driver update.

Fix 2: Check for latest updates of the game
Similarly, check if there's an update to the game itself. If you bought it via Steam, it should be updated automatically. Otherwise, check the game developer's website.
Finally, make sure Windows itself is fully up to date. Unless you chose to disable the feature, updates should be installed automatically.

Fix 3. Configure your Operating System
Low powered systems may not be able to run the graphical features of Windows and League of Legends effectively at the same time.
You can turn off many of the advanced graphical features within Windows to improve your system's performance.
While underpowered machines will see the most benefit from this step, most PCs may see an increase in performance by changing these settings:

1. Right-click Computer
2. Select Properties
3. Select Advanced System Settings
4. Select the Advanced tab.
5. Click Settings under Performance
6. Select the Adjust for best performance radial
7. Move to the Advanced tab
8. Select the Adjust for best performance of: Programs radial

Fix 4: Update Microsoft DirectX
It is a suite of multimedia technologies that helps create the special visual and audio effects that come with games. Many games rely on DirectX to help get more performance from your computer. Make sure that you have the latest version of DirectX so that you can take advantage of all of the latest features.

Fix 5: Use FRAPS utility to measure your actual frame rate.
Launch FRAPS before starting up your game, and look at the FPS figure it provides when you're in the game. Any time that little yellow counter drops below around 25-30 FPS or so, especially in fast-paced games, you're going to feel some amount of graphics lag. If it drops below around 15-20 FPS then you'll really feel it.

You can download it from the below link:
http://www.geforce.com/geforce

I hope this helps in getting a good fps rate and you can enjoy playing NFS without any lagging.

Regards,
Lokesh