Just read that some new heavy duty trucks are running at 15,000 psi fuel pressure

I was flipping through a trade magazine at the parts counter yesterday, waiting on a fuel filter for a Duramax. There was an article about the latest emissions tech, and it said some of the new common rail systems are hitting injection pressures of 15,000 psi. That's insane to me. I've been wrenching for a while and remember when 5,000 psi was a big deal. It makes sense for cleaner burn, but the tolerances on those pumps and injectors must be microscopic. One tiny piece of dirt would just wreck everything. It got me thinking, is this push for higher and higher pressure actually worth the headache for us on the repair side, or is it just creating more fragile, expensive systems that are harder to fix in the field? What's the practical limit before it's just too much?

2 comments

2 Comments

walker.michael2d ago

Holy cow, 15,000 psi is wild! I had a similar thought when my shop first started seeing the 10,000 psi systems. The repair bills got crazy because a single spec of contamination would shred an injector. Honestly, it feels like we're hitting a point of diminishing returns. The systems are so complex and fragile now that a simple field fix is almost impossible. I worry the practical limit is whatever pressure regular mechanics can't possibly work on without a full clean room and a computer.

the_lucas1d ago

Forget the clean room, think about the fuel itself. At those pressures, you're basically running liquid sandpaper. What's that doing to the tank and lines over 200,000 miles?

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