Engine 'carbon cleaning'

[Nogbad the Bad]

I have a 2.4 petrol auto, and get 20 mpg around town and 40 mpg on a motorway run. I used injector cleaner, and noticed a slight increase in throttle response, as well as better mpg by about 1 mpg.

[Kev0607]

Originally Posted by XC90Mk1

The ‘Terraclean’ process has good reviews and I believe to be backed up with data. A work colleague had it done to his 110K focus diesel and found it made good improvements.

I am sure you will find an improvement. Give it a go!

Diesel's have a tendency to clog up more though, so the process probably would work much better on a diesel vehicle.

I'm not convinced that it'll do the same on an older petrol car, like the OP has.

However, its the OP's decision. It may be worth a try once just to see does it do anything, as a test run so to speak. If it does work, then happy days. If it doesn't, then at least you tried & would know for certain that its a waste of money on your particular vehicle.

If anything, it may not give you more mpg, but it'll give the internals a spring clean!

[stuart bowes]

when we say 'old' though are you referring to the older programming in the ECU, older sensors, older style of engine etc

or do you mean old and worn out, because although mine IS 20 years old, it has only done 56k so it's actually barely warmed up, I chose it because it was in such near-new condition

actually if anything that was why I was wondering if it would even do anything, it's not really had a chance to build up crud like a high-miler

but then, why the poor mpg. it's a head scratcher that's for sure

[stuart bowes]

Originally Posted by Nogbad the Bad

I have a 2.4 petrol auto, and get 20 mpg around town and 40 mpg on a motorway run. I used injector cleaner, and noticed a slight increase in throttle response, as well as better mpg by about 1 mpg.

yeah 20 is what Im hoping to achieve. it's still not great but it's better than 17

due to lockdown I haven't really had a chance to measure motorway mpg's

[Kev0607]

Originally Posted by stuart bowes

when we say 'old' though are you referring to the older programming in the ECU, older sensors, older style of engine etc

or do you mean old and worn out, because although mine IS 20 years old, it has only done 56k so it's actually barely warmed up, I chose it because it was in such near-new condition

actually if anything that was why I was wondering if it would even do anything, it's not really had a chance to build up crud like a high-miler

but then, why the poor mpg. it's a head scratcher that's for sure

Old in general... Older engine etc.

[JoeNinety]

I also have a 2.4 auto (2006) V70 and have returned 34 mpg over the last 10,000 miles, local and motorway miles. There is something more wrong with your power train if you are only getting 17 mpg.....

What does your Owners Handbook say about mpg ?

Mine says 9.8 litres per 100km = 28mpg

[davebb]

Hi stuart
Can you look at the MAF , is it a original Bosch unit , not a cheap replacement,
Dave

[Zebster]

Originally Posted by stuart bowes

yeah 20 is what Im hoping to achieve. it's still not great but it's better than 17

due to lockdown I haven't really had a chance to measure motorway mpg's

17mpg is terrible. About what I was getting from a 3L Ford Granada back in the early '80s!

Pretty sure you have a fault and I can't see how Terraclean could possibly fix this (nor any other 'cleaning' snake oil). If anyone tells you otherwise then get them to agree to a refund if a certain level of improvement isn't gained by the treatment. They won't!

I guess it could be the MAF, but it would have to be over-reading to result in such over-fuelling (usual failure modes, including being dirty, normally result in under-reading). I know it's already been mentioned, but I'd really want to positively rule out any sort of brake binding... pretty easy to check for excess heat after a short run with minimal braking. Otherwise pay someone with VIDA (and who knows what they're doing!) to perform full engine diagnostics to pinpoint the cause. This would be a far better thing to spend money on than Terraclean and guesswork!

[stuart bowes]

Maf appears to be original and i assume there isn't some thriving market in fake MAF sensors? Also is not indicating a fault

When i run the car with my VIDA hooked up and look at sensor readings which ones might be relevant to fuel economy? And would it be ok to just do that at idle or would i need to do screenshot under load as well

Again I would point out this is 100% urban due to lock down and others are saying urban 20mpg so it's not actually a million miles off. I don't have a motorway figure yet

[stuart bowes]

Checked wheels numerous times and never hot to touch