Forget all the over priced and over rated tuning boxes out there. I've had two different tuning boxes from Ron over the last few years, and they all transform the way my vehicle drives! ( currently 2011 C200 cdi Mercedes) well done Ron 😊

I have purchased and installed the synergy Ron box 4b to my mk2 ranger 05. There seems to be a torque increase on low revs, but as soon as you get into boost/ under load it judders ! I’ve tried all the setting and played with the off boost fuelling and normal fuel screw and doesn’t seem to make it stop. All connections are connected properly. I’ve tried 2,3,4,5 and doesn’t stop it juddering. Any ideas please ?

Purchased Synergy 4b box for my Mk2 Ford Ranger. I wanted more low down power and better mpg and wow it delivered more than I expected!!! Noticeable power increase and better mpg. Highly recommended if you want more grunt from your older diesel.

Fast and helpful assistance from Ron. My email inquiries were answered promptly - great communication. Good results so far from the Synergy 4B on my non-common rail 3.2 Pajero. Still tinkering to determine my preferred settings but it definitely works.

Excellent product works great on my Ford ranger mk2 definitely improves the way it drive excellent communication Ron is very helpful. Buy one you will not be disappointed.

I cant reccomend these guys enough. Ron went above and beyond when for some reason my phone decided to put in a random incorrect address and so my parcel didnt arrive. Ron was prompt with a response and was so helpful and sent another tuning box out to me. I've used tining boxes for years and over thousands of miles and I have to admit, this tuning box is by far the best one over used. No warning lights, a huge change in driving characteristics and at a very good price. Other more expensive tuning boxes I've used in the past looked the part but caused problems with the car going into limp mode. I've now run this new tuning box for nearly 2000 miles without one quibble and huge performance changes. Thankyou Ron. Adam Horrell

Great product at an amazing price. Ron was very helpful and quick to respond to questions. The Synergy 4b has really transformed my 02 Pajero I’m now able to run 26psi without it going into limp mode it now goes 0-100kph in 8.4 sec it a beast I really enjoy driving it. Boost is almost instant thanks to the Off Boost Enrichment and the extra economy is very noticeable and accelerator pedal is higher when cruising at 110kph. I highly recommend this product to everyone even if you’re not wanting extra power and just economy. Thank you Ron P.s. This is not a fake review I’m genuinely very happy with my $200nz spent.

This must be my fourth Box from Ron (tuning Box) covering a number of different Petrol & Diesel Vehicles, and each time the Bang for Buck has been extraordinary. I've tried the MORE expensive ones and found very little benefit. You get great service somebody on the end of a phone who understands your questions and queries. All round first class service.

I've known and dealt with rover ron at tuning diesels for many years and it's always a pleasure dealing with him thanks to his vast knowledge of my cars (Two rover 75's) and the time he takes to personally explain the technical details to me. I recently bought my second synergy 2a tuning box from him and as Always he was quick to reply to my email and the box was sent by super fast recorded delivery the next day. For the record both my 75's run on 160bhp tuned engines and synergy 2a boxes set to 7 MED/MED one having done so for 10 years now or so. Superb product, great bloke and brilliant company to deal with. Cannot rate highly enough. Ron also recommends Miller's eco and extralube Zx1 Both of which I have used for years and my engines return 56mpg having covered 149,000 and 85,000 miles respectively.

My truck (Range Rover P38 2.5) was sluggish as anything and was constantly going up and down the gearbox to even stay at 45/50mph. It now pulls away like a scalded rat in comparison and gets to 70mph with ease and with the box being as happy as anything, overtaking is VASTLY improved and it has made the truck altogether a far superior machine to what it was. I've not been asked for my input or anything else but when I like a product I'm sure to plug it in anyway possible! Should you buy one? YES, the best £90 I have spent on my car so far. Fuel consumption seems much better too.

I have had a Digibooster S with vaccum solenoid and 30psi MAP installed on my Nissan Patrol ZD30DI for almost a year now. After several months an aftermarket Eclipse turbo was fitted running 27psi and the Digibooster is contolling all aspects of boost bloody marvelous. On the dyno we tested just about every combination in settings and finally settled on vfast/vfast which makes the old girl sing a song I like to hear ;). Spent a bit of time talking to Ron to check suitability seeing as I'm in Australia, he is very helpful. Ross W

Great equipment fast and friendly guys also

Best tuning box I have ever used. I liked the fact there was no ridiculous claims on the website only reasonable comments on what to expect. I am very pleased with the extra performance, and modest improvement in economy, the box has provided.

Bought a Synergy box for my Chrysler Voyager 2.5 - certainly makes it drive "lighter", could do with a 6th gear on motorways now :) Great communication, and makes sure the product has the right connectors prior to sending.

Excellent piece of kit and Ron was helpful in providing advice to ensure correct fitting

Quick service, honest and reliable Highly recommended

This is the second time I have used this company and highly recommend their knowledge and expertise.

Excellent product does exactly what it says on the tin

Excellent product and fast delivery, 'nuff said.

Very quick delivery, good packaging and overall service.