Understanding gasoline direct injection and fuel quality

With the increased use of direct injection and turbocharging in today's engines, the quality of fuel is more imperative than other.

Keeping injectors clean, particularly in direct injection engines, means using detergent-heavy fuel.

Motoring TV fins out why.

(This segment originally appeared on Episode 25 of Motoring 2014.)

***Watch full episodes of Motoring TV at MotoringTV.com***

[GaryL]

Thanks for all of the embedded advertising.

[jonsmith]

this was found in investigations to be misleading. All gas grades in the United States have detergent levels to keep engines clean. premium gas does not lead to cleaner engines or better fuel economy.-unless your car specifically requires premium.

[dadsfave]

Even with detergents in fuel, GDI engines are prone to carbon buildup in the intake manifold. In a port-injected engine, the fuel constantly cleans the manifold. Port injectors, being outside of the combustion chamber, are less likely to get clogged. If a GDI engine requires you to pay for more expensive fuel, isn't that negating some of its advantages?

[garrettm]

I have a couple vehicles with Direct Injection, one is an Expedition with over 100k on the motor and the intake valves are still clean. Turbocharged Direct injection engines are the ones really facing build up issues because the intake valves open while the exhaust valves are open to push out the exhaust gas and cool the cylinder. With both exhaust and intake valves open, the exhaust gasses swirl around the intake and deposits start to form over time. Using a Top Tier fuel and a full throttle blast here and there will keep the engine clean with some additives here and there.

[edwardholmok]

Some manufactures are using GDi and intake port injection to help keep the valves clean.

[RAWRMotorsports]

You forgot about the severe carbon buildup on the intake valves because of gdi .. the ONLY solution is to include port injection on top of the DI

[boostjunkie]

I have seen the before and after of Shell V power 93 and it literally cleans out chunks of carbon off of the valves and pistons

[Layput]

I have been using 98 octane (RON) on Hyundai Sonata 2017 and at 17, 000 kilometers, I have observed a noticeable decrease in performance, especially during acceleration, and a worse gas mileage.

I know my car doesn't require that high octane rating but there is a substantial difference in performance between 95 RON and 98 RON, when the car was newer.

[rasra]

So how do i i kow if i have direct injection?

[davet.]

It's illegal in the USA to claim one gasoline is better than other in any form of advertising. They never say the Shell gas is better just a good idea if you love your car.

[edgarhc]

If you have direct injectors you'll end up with carbon build up on the valve.plus use sea foan to clean, fuel system, engine and also valves

[XRated]

Or do what is called the Italian Tune Up.... floor it, increased pressure to the injectors will unclogge it and loosen carbon within in the heads and valves. But I do use shell V power(because I have to use 91+ octane) along with lucas upper cylinder lubricant and fuel treatment.... I'm supercharged what can I say?

[TheChrisey]

Lol the "detergents" added will simply lower the energy in the fuel, so fuel consumption goes up. It would make much more sense to have proper detergents that can remove carbon externally and add it through the intake or whatever occasionally. There is nothing really that can properly clean carbon without ruining seals or other parts. People are being fooled. Better to use a cleaner fuel that doesn't produce that much carbon. I use E85 in my race engine.

[vwbora]

The guy say 4-5 cents more per liter, how about 22 cents wich is really what it is.

[tylerrichter]

Ignore this garbage, go watch scotty kilmer

[Mienhboi]

Or just buy a fuel additive once in awhile

[AOqueso]

This is just a glorified commercial for Shell

[TheBillproject]

ok.... normally high octane is bullshit in a normal car... and certain brands of fuel sucks. The model engine they show.... it is my Kia sportage sx turbo... 2.0T giving 260hp. It is rated for regular. NOW, in my case... and I was a believer that this all was bullshit, it is true BUT only with certain brands... Power? I doubt it makes it run any faster! Running smoother? yes! starting better? Yes! BUT, because certain brands suck and other are better quality! I can use 87 from brand A and my car runs great! 91 from Brand B and my car coughs and coughs starting up. It is the fuel quality and not necessarily the octane. I had issues for a while and the fix was changing brand... that's it! I use 91 because it runs quieter as well as getting better mileage.

[killerbee]

We need more ethanol in the fuel market not more detergents in gasoline if you want more environmentally friendly vehicles with direct fuel injection and don't have to periodically clean your engine!