Is ELD based on GVWR?

YES. ALL DOT regulations are based of the Gross Vehicle Weight Rating or actual weight, whichever is HIGHER. If your vehicle meets the definition of a commercial motor vehicle then all the rules apply, including hours of service.

390.5 defines a commercial motor vehicle as;
means any self-propelled or towed motor vehicle used on a highway in interstate commerce to transport passengers or property when the vehicle -

(1) Has a gross vehicle weight rating or gross combination weight rating, or gross vehicle weight or gross combination weight, of 4,536 kg (10,001 pounds) or more, whichever is greater; or

(2) Is designed or used to transport more than 8 passengers (including the driver) for compensation; or

(3) Is designed or used to transport more than 15 passengers, including the driver, and is not used to transport passengers for compensation; or

(4) Is used in transporting material found by the Secretary of Transportation to be hazardous under 49 U.S.C. 5103 and transported in a quantity requiring placarding under regulations prescribed by the Secretary under 49 CFR, subtitle B, chapter I, subchapter C.

 

If your GVWR and actual weight are at or below 10,000 pounds and you are not hauling hazardous materials requiring a placard then your truck and driver is not DOT regulated, so no you would not have any hours of service regulations and could work as much as you want.

Something to think about though, just because you are in compliance with the regulation does not mean you are safe or free from responsibility for negligence should you be involved in a crash. A trial lawyer would eat you alive and take everything you own if you were found to be working beyond what is accepted as industry standard.

Also, just because hours of service and other FMCSA/DOT regulations wouldn't apply because of your truck's weight, you may still be in violation of other non-trucking related state specific laws regarding driving while impared, ill or fatigued.

 

That is not correct. The Federal Motor Carrier Safety Regulations have a very clear definition of a commercial vehicle and when each set of regulations becomes applicable. Under 10k GVWR and no hazardous material and you are not subject. Even your minimum required public liability insurance is reduced for $750,000 down to $300,000 for transportation in trucks under 10,000 GVWR.

Here is the link to the majority of the FMCSRs. I suggest you read them and become familiar.

FMCSA Regulations and Interpretations – 49 CFR Parts 300-399 | FMCSA

 

Yes, when you are ready to add a truck over 10,000 GVWR you would have to upgrade your insurance to cover the required minimums for the current operation. If you do the application correctly and do not have any lapse in insurance coverage or other revocation of your authority then it will begin aging on day one when it is active. Keep in mind it takes about 30 days from date of application until MC authority is granted by FMCSA, so you are looking at a month from the day you apply until you are legal to haul anything, then the 180 days after that for the aging that Amazon requires.

 

You have some patience @brian991219