Hello! We recently purchased a 2017 Transit Connect LWB Cargo Van with the 2.5L motor and optional Trailering Package, in which we plan to pull a 10' Teardrop trailer on long extended camping trips. The plan is to cross the desert. The owner's manual calls for the use of 5W-20 oil. Lacking both an oil and trans cooler (to my knowledge), I am concerned that 5W-20 will be too light for the possible work load we could encounter on long grades in high temps, with the viscosity thinning out. In another used vehicle we own, I replaced the 5W-20 that was used with 5W-30 Mobil 1 Full Synthetic oil, with no problems. On a visit to the local Ford Dealer, I asked the Service Dept Manager this question, and he replied that I shouldn't have any problem, and that is what he would do. But he seemed vague, and inattentive, so I wasn't secure in his assertion.
Do you think switching up to 5W-30 Mobil 1 Full Synthetic oil would be prudent in our Transit Connect, and it wouldn't cause any problems other than slightly decreased fuel mileage (such as "setting the Check Engine Light, etc?).
Your thoughts and experienced opinion is valued here, as we hope this vehicle will serve us for many years and problem-free miles. Thank you!
Doug