I've noticed that my turbo boost gauge reads 15 psi when just cruising at 70mph on level ground, not hooked up to a trailer, or anything.

I was told that it should only read about 7 psi............. Is this true ??

If so what could be the problem, or cause of this, and would this explain poor fuel ecomomy too ??

What can I do to fix it ?? and YES, I only have the factory elbow on the turbo too.

Thanks...

 

the real question is drag....and how level? A slight grade (not perseptable by eye) can raise my boost to 15. Ussually I pull 10 psi or so......sometimes 15k sometimes 7.....with slight changes in the road. All of witch I would call level but is NOT. If you pull 15 all the time(no head wind)......I d look at the brakes......which could cause a milaege loss. The 15 psi is not IMO.

Pulling my 50 ft vintage, I run 15-20 on level looking ground. egts about 1100.

pulls 54psi on the hills......

 

I agree on the ground part. I see between 7-10 on perfectly flat ground and 15-20 on seemingly flat ground. If yours is doing it all the time then something is dragging and causing it to read that. It could possibly be a bad gauge as well.