I went up to Terraclean UK's HQ in Newcastle (UK) on Tuesday and they did my car. It took about 40 minutes from start to finish.

CLAIMS:

- better performance
- 10-15% better mpg
- much lower emissions

RESULTS:

Performance: TBH, I have noticed absolutely no difference in performance, although they did say this was not surprising as the XKR has so much power to begin with. I drove a 510hp 2013 XKR the day before and, although it felt much more modern than mine, I can't say I could really feel the extra 100hp that much, so maybe they're right.

MPG: I averaged 25mpg on the drive up and 29mpg (+16%) on the return trip, so this is clearly in line with their claim.

Emissions: unfortunately (and somewhat surprisingly), Terraclean didn't have a gas analyser available, but I will get my emissions checked here in France at an MOT centre and compare them to my last MOT report.

Weirdly (though the engineer who did my car said this could happen), the ECU took until the following morning to adjust properly to the nice clean engine, and it was only then that I saw the fuel consumption improve. When I switched the engine on the next morning, I got a Restricted Performance message on the dash (which gave me a GOD DAMN HEART ATTACK), but I switched off and then on again and it has been ok since. The ECU must have been resetting itself or something.

Overall, then it seems well worth the £80 (approx), though I need to get the emissions checked before it's conclusive.

 

Thanks for the post Frog, I've had this done myself on my A6

I've noticed increased fuel economy and smoother running too.........happy with the result.

I have a thread somewhere on it too, in the diesel section iirc

Looking forward to your updates

 

Frog,

Glad you had such a favorable result. It should pay for itself in short order.

BTW - Had you tried a regular injector cleaner in the gas prior to going Terraclean?

 

Yes, but that is to be expected!
When you look at a map it's all downhill on the way back!

 

Possibly a 'hard reset' after the Terraclean to put the ECU back into default mode would have speeded up the adaptation process.

Graham

 

OK, I can't speak for Frog's trip home, but I did take a trip to Atlanta from Louisiana a couple of months ago, and it is a bit of an uphill drive from Mobile to Atlanta.

I did actually notice almost a two mpg difference between the trip from Mobile to Atlanta and the trip on the way back because I was intentionally interested if it would make a difference, and it decidedly did.

 

I agree there is a psychological impact, but I did over 600 miles in total and at one point saw 33mpg which I have never had before, even when driving ultra carefully.

 

In my case, it was not psychological. I have driven back and forth from Louisiana to Atlanta at least fifty times, and probably more over the last forty years.

I always wondered if the mileage on the car was different, and so this time I checked it very carefully and it actually was. If you think about it, it only makes sense. On the way from Mobile to Atlanta there are stretches where you are going up a mild upgrade or fifty miles or more, and you are, in fact going uphill for the entire drive, while, on the other hand, on the way back you are effectively going downhill for the same distance.

As I said, I don't have any idea if that had anything to do with your mileage, but it certainly did for mine on that particular trip.

Interestingly enough when I filled up with gas slightly outside of Atlanta on the way home, the miles that my car said I could go left me about fifty miles short of my destination, and I left that measurement on for the entire trip, and compared it to the mileage markers on the interstate. (here we have a mileage marker on side of the interstate at every mile) I started to notice that I was gaining miles in my miles to go in my car, compared to the mileage markers, and, in the end I made it all the way home without having to stop for gas again and then when I calculated the gallons used in each direction, it was fewer on the way home, and I actually drove a little faster.

 

How do you do a 'Hard Reset' ?

 

Disconnect the negative battery cable and touch it to the positive terminal for 5 seconds. You will get the same effect if you leave the battery disconnected for a long while.

Afterwards there are a few things you will need to do (reset windows, etc).
https://www.jaguarforums.com/forum/x...ect-faq-74146/

 

+1

Hard reset rapidly discharges the capacitors whereas a battery disconnect only causes slow leakage.

As you are in the UK, be careful if you need to disconnect your battery. You have a coded radio and will lose the code immediately. Make sure you have the 4-digit code available before doing this!

Graham

 

Not to rain on anybodies parade, but gas mileage can differ with time of day, humidity, type of gas. I know for a fact that Georgia has different requirements for ethanol, than Alabama and Florida. I always get better mileage when I fill up in Florida compared to Georgia, because Georgia mandates 10% ethanol compared to Alabama and Florida say it can be up to 10%.

Alright I admit it, I am mad. Had my vette Terracleaned and I did not notice a gas mileage difference, though when I looked at the CO2 and other emission numbers, they were much better compared to before the cleaning.

 

Here is a interesting read about the process.

Solution to the carbon build up - Terraclean? - The Unofficial BMW M5 Messageboard (m5board.com)

 

I read this BMW article about Terraclean and the reaction seemed a little negative from one particular person and to say sceptical would be an understatement. However I did see an episode of 'Wheeler Dealers' where the mechanic did indeed take an XK8 to be Terracleaned and measured the emissions before and after the process. The interesting thing was that whilst the emissions were significantly reduced, it was implied that not only was the engine de-carbonised, but also that the catalytic converter was cleaned and also the entire exhaust.
I do not know the theory on catalytic converters but I thought the process was ceramic absorption of pollutants and I don't know if this process can be reversed. Having said that, the answers are in the emissions figures afterwards (which became like a new car) and there is no need to strip the car.
Now I have years of experience (some might say I'm old) :-) but I remember when I was early 20's doing much work on Mini engines and one engine was a racing engine that would regularly split the head gasket.
The action of small amounts of water (yes water) getting into the cylinders would cause the carbon to combine with the water and the engine when stripped would always be squeaky clean, no carbon.
There was, at the time, a guy who was trying to sell a small system that dripped small amounts of water into the carburettor manifold (vacuum takeoff), claiming this cleaning process as a side benefit of additional power provided by the water becoming super heated steam in the combustion process.
So you see, all this stuff was going on 40 years ago but not packaged in fancy equipment such as Terraclean. But my belief from what I have seen is that for modern cars this is probably a good thing to do once every 70,000 miles.
In conclusion, what have you to lose? Less than the cost of a service and nothing is disturbed.