Sinister Diesel Reviews 

I spent so much money with these people
I ordered parts never received them. I have pictures from the delivery. It was delivered to the wrong house maybe make a police report and they still haven’t sent me my new parts or a refund so I can go buy somewhere else. I’m about to throw away all the junk I’ve ever bought from them Which I’ve had problems with Patty of times.

Been two days for a next day air item and still havent recieved a tracking number. Ordered many parts from riffraff and summit, recieved a tracking number almost immediatley and recieved all parts on time. Whether i recieve my item or not it will be the first and last time i make a purchase with sinister.

The customer service experience, the products sinister diesel is the best diesel performance

my family and I have spent a ton of money with sinister for our 6.0/7.3 powerstrokes, from turbos, to exhausts, to internal engine parts.

I contacted them the other day on possibly seeing warranty period for their oil/coolant filtration system kits, the bracket had a developed a crack in it over the past few years from vibration and harshness of a 6.0 engine bay.

got in touch with Rebecca in their customer service via chat and via phone call. honestly she’s been the EASIEST customer service rep of a big performance parts company I’ve ever dealt with in my 12yrs of automotive performance/repair career.

she went out of her way even at closing time (sorry for running you around Rebecca) to my old order history to see what all I’ve replaced on the truck that I couldn’t find the paperwork for. even offered me some swag and discount codes for being a loyal customer, and all this offered over a warranty parts call!

I’ll be spending my next $1k toy truck budget with these guys again. haters will say it’s photoshopped, but I’ve had nothing but good customer service experience and purchase experience with sinister diesel. you get out what you put in when it comes to customer service and wanting help on warranty repairs/parts in this industry. treat people the way you want to be treated.

Jamie a.

I bought a Sinister Diesel IDM. Less than 2,000 miles later, I was stranded and incurred a $1700 bill to have the truck towed and the IDM replaced. Sinister would not honor the warranty because I didn’t have the diagnosis soon enough! When I called, Sinister said this happens and didn’t apologize or offer me anything except 15% off! I have now removed all their garbage from my truck and will never buy another junk product from them. Save yourself and avoid this company entirely! Poor products and no warranty = fraudsters.

I have nothing to say bad about Sinister Diesel the product I ordered was shipped and arrived when they said it would and on time, there was as advertised, good quality and workmanship, A+ in my book good job Sinister Diesel.👍

UPDATE: Have to say they made this right. I was contacted by a rep and they replaced the item and paid for shipping to return the defective alternator. I couldn't be more pleased with the customer service! INTEGRITY!!

I was given a 250 amp alternator for my birthday approx. 1 1/2 years ago. I wasn't able to install it until 8 months ago because I didn't have time to upgrade wiring. It died this week. $550 + for something that didn't last very long. I do not recommend this product. It's inferior.

Ordered blue coolant hose. Received Lavender colored hose. Hey bros, decorate your engine bay in LAVENDER! Sinister reply... that's what it is. So far no refund, no customer service. They just lost a customer but don't seem to care!

Timely service. Order was correct. Thats all I need.

Great service very easy to install my parts!

Awesome instruction manual!

Fast shipping, easy install instructions.

The cab lights I had ordered were exactly what I was hoping for. Simple plug and play direct replacement. Made it nice and simple. They even throw in a set of directions in case your truck didn’t already have cab lights. Very bright as well. Will definitely be back for headlights, taillights, and eventually more!

Product was priced well and arrived before scheduled. Will be back when we need more products.

Ordered sinister diesel parts for my cummins the parts came quick and fit perfectly. Got lots of gains

I appreciate the quality and quickness of arrival of their parts their welds and craftsman ship. However ups usually does horrible shipment and sometimes leaves knicks and scratches which can be annoying but that’s ups’s fault. All I ask of sinister is more sales products as I feel as some of their items overpriced yet I want to buy 80% of my parts from them I only buy some here and there because they are so expensive compared to oem

Just received my new cat filter and adapter for my 2004 gmc 2500hd. Every thing came quickly and packaged very well. Getting ready to order a Lift pump for my truck next. Thank you

Web site was great! Easy to order and had fast shipping.

Great product perfect fit looks and performance great. Definitely recommend to others