Effect of 17" wheels when towing w/2nd gen 2.7 4 spd auto

Hi all,
just did some searching on the towing forum and it looks like the 2.7 4 cyl with 4 spd auto is a capable (but not peppy) tow rig. I tow a single axle racecar trailer with my VW drag bug (total weight of car/trailer under 2,000 lbs) so I'm way under the 3500 lb limit.

The previous owner fancied things up a bit by replacing the 215/70/15 wheels/tires with 245/65/17 wheels/tires. I have ran the speedometer calculator and the speedo indicates almost exactly 10% low. 60 mph indicated is 66 mph and in top/4th gear of the 4 spd automatic then engine is turning 2,000 rpm at 60 mph (indicated) and 2600 rpm in 3rd gear.

I would expect going back to stock 15" 5 lug wheels and tires would not only fix the speedo but raise the rpm by 10%. My question is anyone have experience towing with a 2.7 4 cyl with 4 speed automatic that had larger wheels and thoughts on how it affected things? Truck also has a shell/canopy on it as well so maybe that helps the aerodynamics a little, the race car trailer is open and the car is small so not like towing a travel trailer. Thanks in advance for any insight!

 

Have you actually checked your speed at 60 mph indicated via radar or GPS? The calculator will say 10% but actual tire sizes vary between brands and some trucks have the speedo off by the factory around 2-5% to begin with. A 15" wheel vs 17" makes no difference, it's the overall height of the tire that determines what speed it turns at. If someone did a brake upgrade, the original 15" wheels might not fit so take a look at that as well. It should tow ok with the 245/65/17 tires but it would feel better with something shorter. I'm running 305/65/17 tires and it tows ok for a 4 cyl but my truck has the 4.10 rear and I would guess yours is around the 3.56 ratio which makes it tougher to turn the taller tires. You could go with a shorter 17" tire and keep your wheels but you could probably find the stock 215/70/15 tires/wheels used on craigslist pretty cheap. The shell will be added weight that will slow you down as well.

 

Thanks JL8Jeff, I haven't checked via radar or GPS yet but need to. My info on the indicated vs actual was solely based on the tire size using the calculator. I have been combing craigslist for used 5 lug wheels/tires and even checked at the local Toyota dealer who has a room full of takeoffs they would sell cheap but they are all 6 lug as opposed to the 5 lug I have now. Looks like the 3rd gen Tacomas gave up on having 5 lug for 4 cyl/2WD and 6 lug for everything else and just went with 6 lug.

 

Found the 4 spd auto gear ratios online and the R&P ratio in the 2015 Tacoma sales brochure and ran the calcs, the difference in RPM in 4th gear between the 245/65/17s and the stock 215/70/15s is insignificant. 180 rpm in 4th and 250 rpm in 3rd.... Since the 17" wheels and tires are already on and only have 5k miles on them I'll stick with them for now and keep my eyes on CL to see if a set of 15s or 16s come up for cheap.

 

icemanhd Unless I missed something you said you have 5 lug wheels. That says you have a 2.4 ltr 4cyl, unless you changed it. If 2.4 you're really down on power. I towed with a almost (header) stock 2.7 5spd for years. In my company trucks and personal. 2k pounds is working these trucks. I pulled a Casita trailer a few miles once in a while, which the truck survived. But' I wouldn't go far.

 

I had a '13 AC 2.7 auto and loved it. I had 17" wheels with 255/80/17 coopers and they only threw the speedo off abou 2 mph. Towing was a different story. Our firs trip out with our 1100 pound, fully loaded, camper and i couldn't get over 30mph going over the muntains. This was also with the LCE header and a AFE drop in filter. Which is why I now drive a '15 DCSB 4.0 manual the '13 was traded in 1 week after the camping trip. I believe if i would have had he manual 5 speed I would have been ok but NOT the automatic

 

I finally got the trailer hitch and wiring installed a few weeks ago and used the Tacoma to tow my drag car and single axle trailer last weekend. It does the job but doesn't take much of an incline to drop the 2.7 4 spd auto from 4th to 3rd on the freeway and if the grade is anything more than a slight incline it occasionally drops down into 2nd. Considering the LCE 2.7 header as a potential upgrade....