Forte Oil Flush. Yummy!

Just downed a bottle and very nice it was too!

Oil was due a change. Engine has done 172k kms and was burning about 800ml/8k kms. Mobil 1 0W-40 was on the dark side but not super black. Wacked a bottle of Forte in and idled it for 40 mins as reccommended for the first time. Dropped it. Never seen such black crap from any engine! Can only describe it as being like liquid soot. Filled it with cheap oil. Ran it up until the fan kicked in. Dropped it again. Almost as black the second time! Cheap oil in again. Ran up to fan kick-in and dropped it the third time. Almost clean. Just a slight hint of brown. Changed the filter and replenished with new Mobil 1.

I didn’t do compression checks before and after because I couldn’t be bothered, so the results are purely subjective. During a 300 mile run to Somerset and back over the weekend, the engine feels a bit more revvy and smoother running, a bit more snappy on the acceleration.  So far, there is no more HLA clatter on start up. Time/miles will tell if the oil consumption has decreased. Will update later.

The only reason I use Mobil 1 0W-40, is because I can get 5L for £30 at Costco here in Watford.

Forte is definitely a good engine flush. All the muck was disolved into a silky smooth consistancy. There were no globules, lumps or flakey hard particles in the flushed out oil. 

£6 for 2l in Tesco at the moment! Stock up for next time… Smile

Hi victor I also did my oil change I put a can of Wyns engine flush then run it for 15 min then dropped the oil out then put in 10/40 semi syn castrol on offer from tesco and I put a full tank of fuel in with a bottle of forte in the tank I’ve noticed that when I come to a stop I can’t hear the engine it’s do quiet you think it had  cut out

OK so here’s an update. After around 1500miles it has used 500ml of oil. Using Mobil 1  0w-40. Could this be the reason? Next oil change I will try some  Castol 5w-30 and see if there is any difference. But that won’t be till next March. The engine is still running smoother than before the Forte.

Forgive me if I’ve read this wrong but are you really using 0/40W?  10/40W semi-synthetic would be more suitable surely?


My understanding is that the 0w refers to the cold flow characteristics of the oil and cannot be thinner than the 40w or 30w at 100 degrees C. Has anyone else had experience of oil loss using 0w-40? Does anyone know the normal working temperature of the oil? Would that be exactly the same as the coolant temp?

Hi Tony,

A pint in 1500 miles is fine. You wouldn’t even get a warranty claim on a new car with that consumption!

If it used to use even less it could simply be that the flush has shifted some carbon which was sealing small gaps. Nothing to worry about and better than letting it build up to gum the rings or valve stems etc.

Re viscosity, here’s an interesting table I put together a while back from manu’s data sheets.

The cold figure is a cranking rating rather than a viscosity number per se. The table also doesn’t show the viscosity index which is a rate of change. 

What this may mean is that at cold running, say 0 - 10C rather than the 40C shown, the 0W oil may be thinner than a 5W or 10W and be disappearing past cold piston clearances though they don’t show any figures for low temp. Iron block engines run larger cold clearances than alloy blocks which can be tighter when cold.

Only my opinion but I would stick with 10W30 as per the book if you can get it or one of the heavier 5W30s.

+1 for the forte.

Worth paying the extra for this over competition.


I’ve seen it raise compression tests by 60 psi.

Hi Rich,

Thanks for the oil info. There’s a lot of misunderstanding about oil (some of it in my head, not my car’s). I hadn’t considered the co-efficient of expansion of iron blocks vs alli. That may account for some unknown oil burning on warm-up. Anyway, I will report back at 1500 miles after the next oil change  which will be in about 8 months time.