Shell Rotella 30w T1 Orange exhaust residue

[Sepress1]

I am experimenting with this oil in air cooled warm/hot weather engines. I am noticing an orange or tan, but more orange, residue around exhaust area of test equipment. Never seen anything like this with any other oil. Thoughts?
New here as you can see, so I appreciate any patience required.

 

[PimTac]

Could it be the fuel? Many years ago, some local off brand stations in my area were selling gasoline with a reddish hue. The explanation was that the refinery which was local also used a certain clay type of filtering. It left a reddish orange color on carburetor parts and exhaust also if you used it often.

The oil could only be blamed if your engine is burning it but with that color I would bet on the fuel.

Any additives in the fuel?

 

[mightymousetech]

Octane booster will leave an orange/red residue.

 

[ironman_gq]

Any chance it's flash corrosion?

 

[Sepress1]

"Sea Foam" is only additive. i will try pure fuel from a different brand.

 

[Kamele0N]

Red or yellow tan on a muffler often shows that gasoline was not sulphur free....

 

[LeakySeals]

The inside of my Escalade tailpipe is orange. From rust. No carbon to protect it. No oil consumption at all

 

[passgas55]

It is a shame Shell would at least put an SL rating on T1. I had a brand new mower and did not get the Shell 30wt because of it.
I can't see where this would cost them a lot of money.

 

[Sepress1]

interestingly, the fuel was regular grade from a Shell station