I have 3G speed from my plan but on my iPhone 8, I have enabled LTE (4G) so from what I have read online it is still 3G but with better connection because I have LTE (4G) enabled. Speeds seem great to me though!
@Alan_K here's yet another customer that's confused by PM's "3G" data plan naming. Please get your team to change it to something less confusing. Fair warnging: I intend to continue taggomg you on every such thread I encounter until the naming has been changed.
If you buy a new 3G plan, you will get unthrottled LTE speeds for about 48 hours. I was getting 10-15 Mbps in the first couple of days and burned up a lot of data using speedtest in the first few days.
After 48 hours, you will still be on the LTE network (you can see the symbol on your device) but the speed of the LTE is throttled down to 3Mbps.
On your phone, you can go into settings and force it to choose LTE (recommended), 3G or 2G (at least on my Nexus 5). I have read some people say that setting it to 3G may give you overall faster speeds than the throttled LTE. I have tested it and based upon my limited testing this does not seem to be true. Under 3G, I got about 3Mbps download and 1.5Mbps upload. Under LTE, I got 3Mbps download and 3Mbps upload. So, I am going to just leave my device setting to LTE. YMMV depending upon where you are.