Top Gear is located in the UK, and each system is shipped from their warehouse via DHL expedited. Due to this, they’ll go through US customs and you will pay an import duty before it arrives. Based on our most recent orders, expect about $50 per exhaust part, paid to DHL before delivery.
US tariff rules changed several times in 2026, and they may change again. If what you’ll pay changes, we’ll update this page.
How it works
You order and pay for your part from us, Sierra Racing Supply in California. Top Gear then ships it straight from their UK warehouse to your door by DHL Express this typically takes about 1 week from order to delivers (~2 business days handling, ~5 business days shipping).
DHL will contact you by email and/or text with a link to pay online. DHL can’t release the parcel until the duty is paid, so pay promptly to avoid delays.
Why isn’t the duty charged at checkout? US Customs sets the exact amount when the parcel arrives, and the rules are changing often. Paying DHL directly means you pay the actual amount and never a padded estimate.
Why we ship direct from the UK
Shipping straight from Top Gear’s warehouse to you gives you the lowest total price. We could bring exhausts into a US warehouse first and ship them on from there. That would add a second freight leg, storage, local taxes, and extra handling, and those costs would end up in your price. Shipping direct also keeps the duty as low as we can make it.
We’ve worked with Top Gear to keep both the part price and the duty as low as possible. We can’t promise an exact duty figure while the rules keep changing, but we’ll always tell you what we’re seeing.
Why Top Gear, and why buy from us
Top Gear exhausts match or beat many name-brand systems for a fraction of the cost. They’re made from 304 stainless steel, with clean TIG welds and thick flanges. We’ve run Top Gear exhausts on our own track car for over 10,000 track miles.
We’re a small California company that specializes in aftermarket Porsche parts. We test every brand we carry on track. We’re looking for the best quality and, where we can find it, the best value without the “Porsche tax”. When you buy from us, you get US-based support, fitment advice, and pricing and returns in US dollars.
Our prices are fair from the start. We don’t build in a big margin just so we can run big “sales” later. This business is a passion project. We love Porsches and enthusiast cars, from canyon drives to track days and HPDEs to wheel-to-wheel racing. We want to help you find the right parts and set up your car for how you actually use it.
FAQ: Tariffs and duties
How much will I pay in duty? About $50 per exhaust part, based on our most recent orders. The exact amount is set by US Customs when your parcel arrives.
Who do I pay, and how? You pay DHL. DHL sends you a link via email/text to pay online. Your parcel ships out for delivery once you’ve paid.
Why isn’t the duty included in the price? The amount is set at the border and the rules keep changing. Paying DHL directly means you pay the actual amount, with nothing padded on by us.
Would I avoid the duty by buying from Top Gear directly, or from another US shop? No. Every UK-made exhaust pays the same duty when it enters the US, whoever sells it. A US shop that stocks UK parts paid the duty when it imported them, and that cost is built into its price.
Is the duty different for 911 and Cayman/Boxster parts? No. The same rules apply to every Top Gear exhaust part.
What if I order several parts? Plan on about $50 for each exhaust part. Larger orders may ship in more than one box.
What happens if I don’t pay the duty? DHL holds the parcel and eventually returns it to the UK. You are still responsible for paying the duty as well as the return freight in this situation.
Will the duty go down? It might. US tariffs on UK goods changed several times in 2026. We’ll update this page as soon as we see a change, up or down.
FAQ: The exhausts
How does Top Gear quality compare to the big names? It’s as good or better. Top Gear uses 304 stainless steel, TIG welds and thick flanges. We’ve run their exhausts for over 10,000 track miles on our own car.
What’s the difference between catless race headers and high-flow catted headers? Catless headers remove the catalytic converters for the most flow and sound. They are our recommendation for any track car since track use can damage stock or aftermarket cats. High-flow catted headers keep catalytic converters that flow better than stock. Catted headers are a great choice for a street car.
Are they street legal? Top Gear’s Catless & High Flow catted headers are for off-road and competition use only. We can’t give specific emissions testing or legality advice as this varies drastically based on your local laws.
Do I need a tune? No, but you may want one to maximize power and prevent any potential CEL (check engine light). On older generations (987.1 / 997.1 or older), the high-flow cats usually do not trigger a CEL. Catless headers always will. On 987.2 or 997.2 generations and newer, the emissions system became a lot more sensitive and CELs are more common.
You can try fiddling with defoulers, some people have success, but the foolproof method is a tune which will ignore the CEL trigger for downstream O2 sensors. The code is still recorded in the ECU, though, so it does not fix any emissions compliance concerns.
What warranty comes with it? You can read Top Gear’s most recent warranty information on their website, here: https://www.topgear.co.uk/terms-and-conditions
We are always willing to assist with any communications to Top Gear regarding issues with your system, please reach out.
Which setup is right for my car? Ask us. Tell us how you use the car, whether that’s daily driving, canyons, HPDEs or racing, and we’ll help you choose.
Questions? Reach out anytime
If you have questions about parts, setup, tariffs or anything else, we’re happy to help. There’s never any pressure to buy.
- Email: Peter@SierraRacingSupply.com
- Phone: (408) 320-6899
- Contact page