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FJ40 Toyota Fuel Efficiency

FJ40 Toyota Fuel Efficiency Jeremiah Proffit Explains the difference in engines

Toyota Land Cruiser FJ40, FJ60, and FZJ80 fuel economy, and more.  

This is a question that I answer a couple of times a week. Of course, the answer is often different because I talk to many people about lots of different variations of Land Cruiser. There are so many variables: stock or modified? Factory engine or engine conversion? Driving style? Even geographical location can have an effect on fuel economy. Just for fun, we thought we would do a relatively unscientific and quick experiment by calculating the fuel economy of a number of Land Cruisers we have currently at the shop. Before I give you the results, I should tell you that the experiment was extremely flawed. There was no control. The vehicles were driven by different drivers, to different places, and I would expect to get different numbers from each vehicle if we had time to actually put each of them through the same test. Still, some information is better than nothing, right?  

For the stock(ish) Land Cruisers. We found 3 that were good candidates for this article. A 1983 FJ40 in completely stock configuration but for a slightly larger than stock tire. We also tested a relatively stock 1985 FJ60 with the same drivetrain and  smaller tire.  Then, we used an FZJ80 with 35s that is built for overloading (so heavier and less aerodynamic) but with the stock engine and re-geared to compensate for tire size. There was also an FJ40 resto-mod we just finished with a 3FE and 5 speed transmission. Deviating further from stock, we tested another FZJ80 with a Cummins R2.8 and an 8 speed automatic and an FJ60 with the same Cummins R2.8 and an H55F 5 speed. To round it out, we calculated the milage on a 1979 FJ40 resto-mod with an LS3 and a 6L80E automatic. Pertinent specs and the results are below. Enjoy!  

1983 FJ40: Engine and transmission 2F / 4 Speed. 31X10.50s with 3:73 gearing 14.4 MPG 

Vehicle driven 139 miles over mountainous terrain, “with mechanical sympathy” I’m actually surprised that the mileage was this good.  

1977 FJ40: Engine and transmission 3FE / 5 Speed. 33X10.50s  with 4:11 gearing 17.3 MPG 

Vehicle driven 225 miles on the interstage and some around town driving and mild wheeling.  Even though this 40 has larger tires than the one above, the mileage was significantly better. This is likely because to the 5 speed transmission. The overdrive allows the vehicle to drive at highway speeds at a lower RPM.  

1979 FJ40: Engine and transmission LS3 6.2L V8 / 6 Speed Automatic. 33X10.50s with 4:11 gearing 13.4 MPG 

Vehicle driven 163 miles and some “hot-rodding”  did occur.  In fact, I reached 104 MPH at one point. It’s also important to mention that this engine was not broken in yet. I would expect the economy to approve over time, especially if a grandma was driving it.  

1985 FJ60 Engine and transmission 2F / 4 Speed 235X75R15s with 3:73 gearing 13.5 MPG 

Vehicle driven 139 miles over mountainous terrain.  You can really feel the engine working to achieve 60 MPH on any Land Cruiser with smaller than 31” tires and a 4 speed. This 60 would benefit greatly by an H55F. 

1987 FJ60 Engine and transmission  Cummins R2.8 / 5 Speed 33X10.50s with 3:73 gearing 23.3 MPG 

Vehicle driven 210 miles over  mountainous terrain. Pretty respectable for as sporty as a 60 is with an R2.8. I’ve actually calculated over 25 MPG with a similarly powered FJ60. 

1996 FZJ80 1FZFE 3 Speed Auto w/overdrive 315X75R16s with 4:88 gearing 10.4 MPG 

Vehicle driven 185 miles. No surprises here, 80s are not known for their fuel economy and this one is HEAVY.  Without the 4:88s, I bet it would have been under 10 MPG 

1994 FZJ80 Cummins R2.8 8 Speed Automatic 285X75R16s with  4:10 gearing 19.7 MPG 

Vehicle driven over 300 miles on the interstate at 75-80 MPH, and it was windy.  

Well there  you have it. Draw conclusions as you will. As I mentioned above. This is far from an accurate study of fuel economy in Toyota Land Cruisers, but it does provide a decent general picture as it were of what MPG you might expect from your Land Cruiser. Plus, we had fun doing it!  Let us know if there’s ever any questions we can answer for you!