new trailer... my Subaru H4 needs your help :)

Pennzoil motor oil
Status
Not open for further replies.
webfors

webfors

Joined
Jun 6, 2006
Messages
5,486
Location
North
A pop-up trailer has suddenly come into my possession. Dry weight is 1493 lbs, with a tongue weight of 170. I own a 2008 Forester, 5 speed manual. Towing capacity of 2400 lbs, with a Class II (3500lbs max) Curt Hitch and 7-pole wiring with a brake control module for the electric brakes on the trailer.

The Forester has had Pennzoil Platinum 5w30 most of it's life, with current fill being Valvoline conventional.

I plan on pulling this trailer on 3-7 hour road trips with my family for the next couple of summers.

The Subaru manual recommends a range of weights under severe conditions, all the way up to 20w50.

I'm looking at the following options:

R T5 10w30
R T6 5w40
Mobil 1 Turbo Diesel Truck 5w40

And of course, because I want solid conventional options Rotella or Delo 15w40.

All are easily attainable and would work well for this application.

Thoughts and/or suggestions? Would anyone stick with a standard SM rated 30 weight for this type of application?
 
Lucky you! Have fun. The trend I get from used oil analysis is that the NA engine is easy on oil. I wouldn't hesitate to continue to use the 5w30 in either conventional or synthetic. I would change more often perhaps with a conventional.

My personal choice in your circumstances would be a 15w40. I ran a Castrol Tection OCI last summer and my unscientific analysis was there was no impact on fuel mileage (33 MPG in the Impreza). I find the new T6 and T5 not to be cost effective. I think there is a special out now on Delvac.

Of course you'll also be checking differentials, transmission fluid, cooling, and tire ratings for the load so hope this little bit helps.
 
15w40 eh?!
grin2.gif
For 3-4 months of summer use it might be the perfect choice.

I'm meticulous about checking/replacing driveline fluids. I'm currently running Motul Gear 300 in the transmission and rear diff. Coolant was replaced at 30k miles.

Regarding tire pressure, you're not kidding. The manual calls for 29psi in the rear tires under normal loads and 41psi when towing.
 
I'd suggest driving it across some scales once you are fully loaded for a trip (with everyone in the car) and see how it turns out. Camping trailers are often significantly different than the weight you expect based on the mfg. numbers. It is also hard to guess how much weight you add and where it ends up. Plan a short trip for the first check just in case you find you are overloaded or need to adjust tounge weight. You need to be between 10-15% tounge weight. Too little and you'll have trailer sway issues, too much and your rear axle might be overloaded.
 
I stick with 5-30 in the Highlander when I tow, but that's more than I've ever towed and much further.

I'd probably go with either 5-40 if I was in your situation, and head back to 5-30 when winter was on it's way even if I had another trip or two. Rotella is probably cheaper and easier to find, so I guess that gets my vote.

Really, though, I worry more about my transmission. Engine temps never elevate. With a manual, you don't have that worry, but easy on the clutch.
 
Last edited:
In your situation, my choice would without a doubt be the Rotella 'T6' 5W-40 - easy to get, relatively inexpensive, and very tough to boot.

I wouldn't use less than a 40-weight in these conditions.
 
Many of you have seen the subaru viscosity recommendations before. Here they are just in case:

visc_h4%20001%20%28Large%29.jpg


The only viscosities not mentioned are 20 weights. That leaves a whole lot of options.

Addguy, what about Rotella or Delo 15w40? Keep in mind I'll be doing the warranty mandated OCI of 6k km (3750 mile).
 
If cost isn't an issue for oil selection during towing season, should Redline 5w30, or even Redline 10w30 (with an hths of 3.8) be considered above the other options already mentioned?
 
Redline is overkill.

I stick by my rec. of a syn 5W-40 HDEO. Sure, 15w40 will work, but I'd go with the 5W-40.....
 
Jeez, they don't fool around with the light weights for towing eh.
Straight 40 weight might be a bit heavy for too many near freezing starts...
I'm happy to run rotella 15W40 during the summer for my cars for some "severe" service, its API SL rated so its good to go in your car too as per your manual.
 
I have towed a ~2000 lb. pop up with an 07 Forester and it does quite well but it struggles on the hills. Never been through mountains with it, but I suspect it would really struggle to maintain speed. The camper had clearance lights all around, and it really seemed to hit the alternator turning them on. I've thought about installing a higher output alternator or swapping out the incandescent lights for LEDs. Make sure your trailer brakes and controller are working and adjusted right, and get those trailer tires inflated properly. Those small 13" wheels need 80 PSI, and don't skimp on that or it will increase drag and wear down the small tires really fast. The Forester needs the 41 PSI in the rear tires while hauling. I would suggest keeping the tongue weight down to about 8-9% of the trailer weight to keep the load as level as possible, otherwise the front end wants to rise up and everybody will be flashing their brights at you.

As far as the oil, we ran Havoline 5w30 for the entire towing season and it worked out great. The 2.5 boxer needs all the torque it can get for towing, so I didn't want to load it up with heavier oil on top of everything else. T6 would be a good choice. Any 5W-40 should do great for you.

Do you have a trans cooler?
 
3750 mile OCI for warranty? I'd just stay with the Valvoline 5w30 conventional (or if you want to get racy 10w30) and get on with it.

The engine and oil will be fine.

Take care and enjoy the trailer! Bill
 
Originally Posted By: J. A. Rizzo
I have towed a ~2000 lb. pop up with an 07 Forester and it does quite well but it struggles on the hills. Never been through mountains with it, but I suspect it would really struggle to maintain speed. The camper had clearance lights all around, and it really seemed to hit the alternator turning them on. I've thought about installing a higher output alternator or swapping out the incandescent lights for LEDs. Make sure your trailer brakes and controller are working and adjusted right, and get those trailer tires inflated properly. Those small 13" wheels need 80 PSI, and don't skimp on that or it will increase drag and wear down the small tires really fast. The Forester needs the 41 PSI in the rear tires while hauling. I would suggest keeping the tongue weight down to about 8-9% of the trailer weight to keep the load as level as possible, otherwise the front end wants to rise up and everybody will be flashing their brights at you.

As far as the oil, we ran Havoline 5w30 for the entire towing season and it worked out great. The 2.5 boxer needs all the torque it can get for towing, so I didn't want to load it up with heavier oil on top of everything else. T6 would be a good choice. Any 5W-40 should do great for you.

Do you have a trans cooler?


Excellent advice! Nice to hear I'm not the only one towing with the Forester!

It's a manual transmission, no trans cooler.

I had the pleasure of driving a utility trailer around town on the weekend with a 2000lbs load. It was well balanced and my tires were definitely not at 41psi. It pulled ok, but you could definitely feel the weight.

What about a standard name brand 10w40 conventional? I'm asking cause I know Addguy likes Motomaster products, and they have their Formula 1 oil on sale this week, which includes a 10w40 viscosity.
 
Originally Posted By: webfors
Originally Posted By: J. A. Rizzo
I have towed a ~2000 lb. pop up with an 07 Forester and it does quite well but it struggles on the hills. Never been through mountains with it, but I suspect it would really struggle to maintain speed. The camper had clearance lights all around, and it really seemed to hit the alternator turning them on. I've thought about installing a higher output alternator or swapping out the incandescent lights for LEDs. Make sure your trailer brakes and controller are working and adjusted right, and get those trailer tires inflated properly. Those small 13" wheels need 80 PSI, and don't skimp on that or it will increase drag and wear down the small tires really fast. The Forester needs the 41 PSI in the rear tires while hauling. I would suggest keeping the tongue weight down to about 8-9% of the trailer weight to keep the load as level as possible, otherwise the front end wants to rise up and everybody will be flashing their brights at you.

As far as the oil, we ran Havoline 5w30 for the entire towing season and it worked out great. The 2.5 boxer needs all the torque it can get for towing, so I didn't want to load it up with heavier oil on top of everything else. T6 would be a good choice. Any 5W-40 should do great for you.

Do you have a trans cooler?


Excellent advice! Nice to hear I'm not the only one towing with the Forester!

It's a manual transmission, no trans cooler.

I had the pleasure of driving a utility trailer around town on the weekend with a 2000lbs load. It was well balanced and my tires were definitely not at 41psi. It pulled ok, but you could definitely feel the weight.

What about a standard name brand 10w40 conventional? I'm asking cause I know Addguy likes Motomaster products, and they have their Formula 1 oil on sale this week, which includes a 10w40 viscosity.



Your subie will be just fine on what you've been running it. No need for an HDEO or heavier oil. If you have 3750 oci for warranty, stick with a good conventionoal, Pennzoil conventional, Valvoline conventional, Quaker State Conventional, and run it for the oil change. Stick with 5w30, it will be fine. If the engine is supposed to use 5w30, and it is rated to tow, it will be fine, otherwise it would say "if towing use 10W-40" or something.
 
Originally Posted By: Bill in Utah
3750 mile OCI for warranty? I'd just stay with the Valvoline 5w30 conventional (or if you want to get racy 10w30) and get on with it.

The engine and oil will be fine.

Take care and enjoy the trailer! Bill


Correct, 3750. My first instinct was to put a 10w30 in for the summer and towing season, and I happen to have some Quaker State 10w30 in my stash.

I guess the real question is does the application warrant a thicker oil, as recommended by the manual, or would everything be just fine with the current fill of Valvoline conventional, as Bill mentioned.
 
Status
Not open for further replies.

Similar threads

john_pifer
  • Locked
My Take on the New 2022 WRX
6 7 8
Replies
147
Views
18K
avacado11
Back
Top Bottom