The 40% off Black Friday promo code at the top of this page is the lead offer from AeroFlow Dynamics. It is a sitewide code that takes 40% off car parts and accessories and is best for larger orders where a straight percent reduction saves more than a small first order perk. Use it when you want the biggest percent off a single purchase; the code cannot be combined with any other offer.
Small carts under $99: If your parts list totals less than $99, the 40% promo code at the top still gives the largest cut, because the 10% first order code requires a $99 minimum. For example, on an $80 order the 40% promo code reduces the price to $48, a $32 saving. The 10% first order code is not available because it needs a $99 first nationwide shipping order.
First nationwide shipping orders of $99 to typical parts purchases: If this is your first nationwide shipping order and the pre discount total is at least $99, the 10% off promo code above applies and also includes free delivery when you meet the $99 threshold. For modest carts it may be simpler to use the 10% off code if you prefer the first order shipping benefit, but the 40% promo code will usually save more. For example, on a $120 order the 40% promo code brings the total down to $72 (40% percent off, saving $48) while the 10% promo code brings it to $108 (10% percent off, saving $12).
High value items and bundles: For large purchases such as forged wheels from $2,499.99, suspension around $999.99, or exhaust systems from $399.99, the 40% promo code is the clear winner. On a $2,499.99 wheel order the 40% promo code reduces the price to $1,499.99 (40% percent off, saving $1,000.00), compared with $2,249.99 with the 10% code (10% percent off, saving $250.00).
Buying marked deals or sale items: The site shows specific item prices, for example forged wheels from $2,499.99, suspension under $999.99 and exhaust from $399.99. The 40% promo code is stated as storewide; use it on those marked items unless the item or checkout flags an exclusion. The 10% first order code cannot be used with other offers, so it will not stack with sale pricing unless checkout specifically allows it.
Choose the code that leaves the lower total for your cart. If you meet the first order and free shipping conditions and your cart is small, the 10% code plus free delivery can be convenient, but for any cart where 40% of the total exceeds the 10% saving, use the 40% promo code. Our records show five offers listed for AeroFlow Dynamics in the 12 months to November 2026, the biggest percentage code in that window was 40% off, and our team ran two checkout tests across two offers in the 12 months to November 2026 with screenshots kept as proof.