Can You Restore Lost Power To An Old Engine? #TBT - Fifth Gear

horsepower how much you reckon your car has by reading car magazines and handbooks we all think we have the answer but do we really know when engines get older their parts begin to wear and that causes a drop in power there's even a myth amongst petrol heads that engines will lose one brake horsepower per year today I'm testing this myth and investigating whether it's possible to restore any lost power my guinea pig is his 1995 Volkswagen Corrado vr6 VW claimed it had 190 brake horsepower when you last week we put this well-maintained machine on a rolling road which revealed it's got just 177 brake horsepower and that's not quite one brake horsepower your loss but it is a lot less than a manufacturer promised we're new so we're going to find out if we can turn this back to its original health nurse fetch me a defibrillator I'm going to try a variety of power restoring techniques after testing each we'll see what effect they've had on the engines power step one is to clean the fuel system there are several potions on the market which claim to restore power by clearing out the gunk that builds up in the fuel line's pumps and injectors we've used a five pound bottle of fuel additive as per the instructions and run the car for a week to give it time to work okay let's get the Corrado on the rolling road the equipment sensors will detect even my new changes in horsepower by measuring the forces sent through the wheels to make sure we get an accurate result we'll do each test eight times and take the highest figure so has the fuel additive made any difference right let's have a look at the results then the red number is after the red X treatment green is before and as you can see that's a big increase that's best part six horsepower what's happening is inside all the fuel lines and particularly injectors they get clogged up with dirty deposits and this red X will have cleaned that out making everything work more efficiently back to almost like how it was designed to but it's important to remember you can't just keep putting more and more that stuff in because once it's clean it's clean so then we've got to look for other ways to try and recover some of the Lost Power but that is a great result next some changes that we'll be routinely carried out during a regular service starting with a new air filter it's designed to stop dust getting into the engine but if it's clogged up it could be impeding air flow and limiting power typical of older cars our Corrado is full of leaves which probably isn't helping now an oil change and a replacement of the oil filter as an engine operates microscopic pieces of metal wear away and get contained within the oil now these tiny particles increase the internal friction of the engine and the results a loss in power so an oil change in a new filter should benefit the engine it will cost around 45 quid plus labor if you're not doing it yourself but will it help call back any more of that lost power to ensure that our results are accurate the system will cleverly compensate for any changes in air temperature between tests that might affect the engines performance right you're not looking you're not looking I am oh that's not bad look two horsepower in oil oil filter and air filter that's only what four horsepower a bit off what it was when it was new come on more work my final route to restoring power is to help the engines ignition by replacing the spark plugs and their leaves I'll be maximizing the engines ability to ignite its food this is expensive at 73 quid for six plugs and 163 quid for six leads but we're to help boost our power back to level it was that when the car was new mega results let's go right the way back to the beginning standard car 177 horsepower what you'd kind of expect next one is with the red X 183 quite a big jump then the purple one here 185 that's oil oil fit filters and air filters and then the last change with all of them plus spark plugs and plug leads 188 horsepower over 11 difference that's what five percent and only well less than two shy of what it originally came with when it was new I would have thought that's a great day's work when driving the car before carrying out the work I noticed some throttle hesitation between three and four thousand revs so after our fettling can I feel any difference actually you can it's definitely more grunt throttles much sharper gone is the hole that was in the Rev band the power delivery back mid-range actually not gone completely but it's much better we spent three hundred quid get in the Corrado back to virtually its original power but if you're on a budget we'd recommend using the fuel additive which in our test just a fiver was by far the most cost effective treatment now that's a great result well well done now that's in the workshop still docked rusting it by to the limit now let's see if I can go that bit for

Channel: Fifth Gear

Views: 1,411,741

Rating: 4.8725071 out of 5

Keywords: Fifth Gear, car, review, fast, fifth, gear, Jason Plato, car review, Corrado, VW, Car maintenance, mechanics

Id: efIJHf7h5kI

Length: 6min 19sec (379 seconds)

Published: Thu Apr 28 2016

Reddit Comments

[u/Xenu503]

LPT: Perform regular maintenance on your vehicle, it will run better and last longer.

[u/jubalearly7471]

I have always had the impression fuel system cleaners were kind of a scam - I stand corrected.

[u/Outboard]

Seems like an advert for Redex fuel system cleaner. It's the best ya'know :)

[u/HardcorePhonography]

Seafoam would be a lot more effective since it's used in both the fuel system as well as the crankcase.

Just don't do it in a residential area, on poorly maintained cars it will produce more smoke than Snoop Dogg's tour bus.

[u/Triggery]

richard hammond sure has let himself go

[u/dilltastic]

This was a cool video, but they really could have done a better job controlling for variables. For one, the dyno being outside makes a huge difference. The ambient conditions themselves could have accounted for a few bhp gain/drop. Also taking the max of each set of runs seems odd. I feel like an average would have given better data. You can definitely follow the trends and conclude that these things probably help gain back some lost power, but to try to compare it to the manufacturer stated bhp from factory isn't a good idea. Different dynos can measure very different hp numbers for the same car.

[u/evergreen35]

Off to buy some fuel cleaner!

[u/WingerRules]

Genuinely surprised at the results from the fuel system cleaner/gas additive.

[u/UltimateDude121]

No, I can't.