Sinister Diesel Reviews 

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

Excellent product will absolutely use this service again

I ordered 3 Auto Meter gauges, so far I have only received 2 of them but they look great. Cant wait to get them all so I can hook them up.

Been buying from sinister Diesel for awhile now and will continue to because of the quality of products and the customer service experience.

Ordered charge pipes and the process was easy. However, 12 days later the product hadn't even shipped with only one notification staying out would ship in 1 week. 10 days later it still did not ship. Sent an email to cancel order and they responded the same day.

I purchased several items from Sinister and was impressed with the over all quality of them.They look fantastic and have improved my trucks appearance and performance.I plan to do a lot of business.Keep up the good work Sinister

I ordered and intake for my chevy pickup Sept. 14th 2020. I got comfirmation of the order and they charged my credit card for the item. A couple of days later I got an email that my intake was backordered and it would be 4-6 weeks before they would ship it. I cancelled the order and asked them to refund my credit card. It has been a week since I cancelled the order. I have called and they said I would get my refund within 5 business days. It has been 6 days and no refund!!!!! I need my money back. I don't want to pay interest on my money and wait 6 weeks for my part!!!!!