Why techron is recommended as a cleaner is not only because of its incredible cleaning abilities but how it burns completely in the combustion chamber. Many additives don’t and leave residue on both o2 sensors and the catalytic converters damaging both in time. When there was nothing past the headers good fuel and cleaners didn’t matter quite as much, now it can be critical. Not all fuels are equal and the alcohol added is a whole different story on how it how attracts water and creates many issues.

there are very few other additives besides techron that won’t muck up the sensors and they are both hard to get and often expensive.

as for using it for normal cleaners not sure it’s needed. Using good quality fuel, not letting the fuel tank get empty (running above 1/4 tank) and red lining the engine on occasions is often good enough to keep and engine and the fuel system running good for years.

poor quality fuels don’t have all the additives or detergents designed to keep the finely tuned engines running properly over time 2-300,000 kms. It’s when systems age that the problems start to show. I and a few friends burnt out Mercedes exhaust systems and engines running poor fuel.

 

That's true I used to do alot of that when I worked on the flight line at a FBO & Air National Guard.

 

Wawa started here in the Philly area, and they are practically on every corner. I've never heard anything problematic about Wawa gas here. If there was an issue, it would definitely be newsworthy in Philly.

I don't usually get gas there, tho, because there's a Sam's Club around the corner from me where premium is generally $.60+ cheaper ($.80 cheaper this week). But Wawa coffee and hoagies are great....

 

Wawa gas, not "TopTier", I wouldnt hesitate to buy it. Same with Sheetz.

 

so, when i bought the m35i, the tech and service advisor who were going over the features and such after the saleswoman had done her job, told me to use top-tier premium (i use 91 chevron, 91 being the highest we have in california) as well as liqui-moly dijectron as frequently as the bottle requires to try to avoid walnut blasting because they were advised that i had purchased the car and not leased it and so were trying to give me tips to avoid walnut blasting the car in the future. i don't think the b48 engine has a tendency to develop carbon deposits so heavy that walnut blasting is required, but i'm going to use the product here and there because yeah, i am buying the car and i can't decide yet whether i'm going to get rid of the car sooner than the five years it's under warranty or whether i'm going to keep it for that amount of time.

decisions, decisions...

 

Fuel additives will do absolutely nothing to stop carbon deposits on the intake valves. And you'll be fine during the first 5 years for sure - as the deposits accumulate the car will start to gradually lose performance and fuel economy, but we are not talking major reduction. Its by the time these engines have about 100k miles where the carbon build up start to cause major issues, where it prevents the valves from fully closing and the engine starts to misfire.

These deposits can only be cleaned mechanically, with a combination of scrubbing, solvents, and walnut blasting. But at 100k, these engines are pretty much done for anyway.

 

that's both good to know and also sad to hear. to have planned obsolescence so firmly in place that a bmw engine cannot last more than 100k miles without major servicing is a bummer if it were to really love the car and want to keep it. now, i don't see that happening with this car, but hypothetically...

 

Depends on the design of the fuel-injection system itself. DI systems sometimes have that problem because they squirt the fuel directly into the cylinder, bypassing the intake-valves for the air.

 

right, if it's direct and port injected then you're unlikely to run into problems, but the vehicle that i own is only direct injected

 

Toyota/Lexus has had the dual injection (direct+port injected) V6 engines since 2007 which prevents carbon buildup in the port intakes. That's more than a decade. How come the German luxury marques like BMW, who are hyped for being on the cutting edge of engine/powertrain technology, couldn't implement this decades old technology in their engines and thereby improve lifespan and ease maintenance issues of their engines?

 

fuel economy. europe is extremely stringent on fuel economy standards.

 

Because its a lot of extra parts and having injectors switch on the fly in a FI engine can also cause issues. Plus by 100k miles there are going to be a bunch of other issues with the car as well as outdated infotainment tech.

 

Does dual injection automatically mean poorer fuel economy?

Those extra parts haven't adversely impacted the reliability of the 2GR-FSE/FXS/FKS dual injection V6s. In fact it's prolonged their working lifespan. Just because other parts of the car will have issues by 100K doesn't mean engine longevity issues shouldn't be addressed. Unless you're saying the German philosophy is planned obsolescence so they don't even try to engineer an engine to function beyond 100,000 miles.

 

Its just a different mentality. German carmakers aren't focused on long term durability the way Japanese ones are.

 

There is no real incentive for the Germans to do that. For decades so many people will gladly pay so much money for unreliable German/Euro brands where it is generally a good idea to get rid of them out of warranty or know a good mechanic. High maintenance costs and expensive repairs are a major profit/money generator for German brands, in some cases likely critical so their cars are just not designed to last very long without expensive maintenance and repairs down the line once the warranty is up, they are actually in many cases designed to fail in certain areas at a general set time, many people in the industry even admit this, sometimes the engineering going into planned obsolescence cost more then engineering a working part itself. The Germans often use newer tech/offer more luxury sooner because the engineering to make it last past warranty is not really there for one thing where the Japanese take more time to make sure the tech/feature lasts longer, does not cost so much to implement, or is even worth it. There are exceptions to this, some older Mercedes cars were known for being very reliable, Porsche 911's are known for being pretty reliable and trouble free, it seems the current gen Mercedes cars are much more reliable then previous gens but based on how well German lux brands sell there is just no real incentive for them to make them as reliable/inexpensive to maintain as the Japanese do, it will actually cost them money if they do that so there is even less incentive.

The Japanese just have a different philosophy and business model with cars, they don't want to be known for unreliability nor do they rely much on replacing things that fail/expensive maintenance, their vehicles may not be as fancy, cutting edge, brands don't have the history/prestige but you get a much cheaper vehicle to own especially long term. Their buyers have different priorities too, they generally will not put up with unreliable Japanese models and will move to other brands quickly if the ownership is painful, the brand/prestige simply is not there with Japanese brands where owners may put up with it to have that much more prestigious Mercedes, BMW, or Range Rover in the driveway.