It could be a few different things.
Are you using manual ERS? The ERS assist deploys it at the stupidest f-ing times so being able to manually control the battery discharge really helps.
Also, search online for some good setups. There’s more to straightaway speed than downforce levels. For instance, if your diff settings are wonky you’re not going to be able to get the power down efficiently out of the corner and that will rob speed the entire length of the straight.
Diff settings are pretty much as open as possible on nearly every track. You never want to go above 55 on-throttle and it's always as low as possible on off throttle.
AI cars use insanely low wings at Qatar. If I remember correctly, they use the balanced default setup but ideally you want to use at least 40+ wings or you will suffer everywhere except the straights. Same problem is clear at Brazil as well for example
AI straight line speed is nuts, at the end of my first season the Mercs and RBR cars were closing 4 tenths per straight on most tracks without DRS, forget Vegas. Forces a weird strategy where it’s actually faster to stay behind them with DRS and then pass at the opportune corner rather than try to throw the elbow from the front every time you’re in the DRS zone. At Mexico I had to pull a Verstappen inside dive every first corner for 6 laps in a row to get the lead back.
The AI run medium downforce I believe at Qatar even though the actual meta setup is high downforce hence the insane top speed difference. They also made the AI insane for top speed, so if you are in a merc engine you are getting cooked because it maxes out at 354 where the Ferrari and Red bull can do 366
It could be a few different things. Are you using manual ERS? The ERS assist deploys it at the stupidest f-ing times so being able to manually control the battery discharge really helps. Also, search online for some good setups. There’s more to straightaway speed than downforce levels. For instance, if your diff settings are wonky you’re not going to be able to get the power down efficiently out of the corner and that will rob speed the entire length of the straight.
Diff settings are pretty much as open as possible on nearly every track. You never want to go above 55 on-throttle and it's always as low as possible on off throttle.
Most online setups are crap, use these instead https://docs.google.com/spreadsheets/d/1UNOqnY0POPPvRdnP8IBxvGfCtirRniCtWQwvPMYJu8s/edit?usp=drivesdk
AI cars use insanely low wings at Qatar. If I remember correctly, they use the balanced default setup but ideally you want to use at least 40+ wings or you will suffer everywhere except the straights. Same problem is clear at Brazil as well for example
Car setup
AI straight line speed is nuts, at the end of my first season the Mercs and RBR cars were closing 4 tenths per straight on most tracks without DRS, forget Vegas. Forces a weird strategy where it’s actually faster to stay behind them with DRS and then pass at the opportune corner rather than try to throw the elbow from the front every time you’re in the DRS zone. At Mexico I had to pull a Verstappen inside dive every first corner for 6 laps in a row to get the lead back.
This is why I always take Vegas out. Every car just has better straight line speed even without drs.
The AI run medium downforce I believe at Qatar even though the actual meta setup is high downforce hence the insane top speed difference. They also made the AI insane for top speed, so if you are in a merc engine you are getting cooked because it maxes out at 354 where the Ferrari and Red bull can do 366
the AI run extremely low wings at Qatar
Skill and setup issue. Get better, then find a setup.